tag:blogger.com,1999:blog-12982032889646579742024-03-16T19:52:24.093+01:00Façades ConfidentialStories about façade design, technology, materials, history and performance.
From architecture to building envelope physics to maintenance to you name it...
Plus lists of façade consultants and façade contractors around the world.Ignacio Fernández Sollahttp://www.blogger.com/profile/03918193520738485621noreply@blogger.comBlogger36125tag:blogger.com,1999:blog-1298203288964657974.post-68327400746628118112013-06-30T23:21:00.001+02:002013-07-30T21:33:00.778+02:00Is Oriel Chambers the first curtain wall ever?<br />
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<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/-Uc1Y4dMpCIU/UdCjRR2HdFI/AAAAAAAAAuQ/9mr_pxCQKvM/s1078/Imagen+1.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="640" src="http://2.bp.blogspot.com/-Uc1Y4dMpCIU/UdCjRR2HdFI/AAAAAAAAAuQ/9mr_pxCQKvM/s640/Imagen+1.png" width="481" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Oriel Chambers, 14 Water Street Liverpool. Peter Ellis 1864</td></tr>
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Back to oldies. In October 2012 I was invited to an architectural seminar in Liverpool, organized by <a href="http://www.spaintiles.info/default.aspx?&lang=en-GB" target="_blank">Tile of Spain</a>, to discuss about ceramics in facades. Another speaker was Maurits Van der Staay, an associate in <a href="http://www.rpbw.com/" target="_blank">Renzo Piano Building Workshop</a>, who presented their terracotta façade on <a href="http://facadesconfidential.blogspot.com.es/2010/11/central-st-giles-piano-goes-to-london.html" target="_blank">Central St Giles London</a>. The morning after the venue Maurits and I re-visited two architectural jewels in Liverpool: Oriel Chambers in 14th Water Street (1864) and a similar office building in 16th Cook Street (1866). This post will remind us about these two buildings and their now forgotten architect; and in particular how they deserve credit as some of the first examples of a lightweight glazed façade – a real curtain wall – installed in a multistory building. Please take note of the dates again, 1864 and 1866: that means only thirteen years after the Crystal Palace and thirty years before the design of pioneering Chicago School facades as the Reliance or the Fair Store. Real oldies, right? <br />
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<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/-fO2o-84ykx8/UdCmHXetZtI/AAAAAAAAAug/bF33ZLS5d24/s1600/MvdS-121026-201.jpg" imageanchor="1" style="clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="640" src="http://1.bp.blogspot.com/-fO2o-84ykx8/UdCmHXetZtI/AAAAAAAAAug/bF33ZLS5d24/s640/MvdS-121026-201.jpg" width="382" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">16 Cook Street Liverpool. Peter Ellis 1866. <br />
(Image from Maurits van der Staay 2012)</td></tr>
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The <a href="https://en.wikipedia.org/wiki/Curtain_wall" target="_blank">Wikipedia entry for <i>curtain wall</i></a> has two images of Oriel Chambers and 16 Cook Street, and it refers to them as two of the world's first buildings to include a curtain wall façade. By this they mean a fairly glazed multi-storey building set in an urban context; not a warehouse, a dockyard or the gable of a large train station. Let’s reckon from the start the impossibility of determining what the real ‘first’ curtain wall was, since the development of any building system is an evolutionary process moving through several directions simultaneously. But it’s time to give Peter Ellis, the architect of Oriel Chambers and 16 Cook Street, the merit he deserves as one of the pioneers in curtain walling, regardless the fact that his influence was small, if any. <br />
<br />
The available literature on these two buildings is scarce. It is clear that their author was <a href="http://en.wikipedia.org/wiki/Peter_Ellis_(architect)" target="_blank">Peter Ellis (1804-1884)</a>, a local architect and surveyor about whose life and work there are strong shadows. These are the only two buildings clearly attributed to him; we don’t know if Ellis signed any other project in Liverpool or anywhere else. There are no records of his previous and later activities: he may have been a surveyor, a civil engineer, or a developer before designing Oriel Chambers and 16 Cook Street; and apparently he went back to surveying or to other businesses after finishing the second building in 1866. The reason seems to be found in the fierce critics with which the two buildings were received at the time, but we will come back later to that. <br />
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/-TM9iqAp9i3o/UdlD2lr37OI/AAAAAAAAAuw/R_XnNGqcEHw/s1600/03+Oriel+chambers_exterior+with+neighbours.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="216" src="http://2.bp.blogspot.com/-TM9iqAp9i3o/UdlD2lr37OI/AAAAAAAAAuw/R_XnNGqcEHw/s640/03+Oriel+chambers_exterior+with+neighbours.jpg" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Oriel Chambers among its neighbours facing Water Street</td></tr>
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<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/-xmKyBaswscs/UdlEZsaQyYI/AAAAAAAAAu4/l3DaTNKj4wo/s1600/04+Oriels+view+1.png" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="640" src="http://1.bp.blogspot.com/-xmKyBaswscs/UdlEZsaQyYI/AAAAAAAAAu4/l3DaTNKj4wo/s640/04+Oriels+view+1.png" width="600" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Oriels and stone: it's not all glass!</td></tr>
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Both buildings have been designed with the same purpose: office space for rent in the shape of chambers. A <i>chamber</i> is what the Americans would call <i>suite</i>, that is, a small office valid for any purpose; whether legal, financial or commercial in general. Each chamber was supposed to be rented for a private business with a small number of users, between two and ten generally. There is little space for sumptuosity, and above all no plan space to be lost in halls or extra money to be devoted to architectural features on the façades.<br />
<br />
<b>The Oriel Chambers building </b><br />
It seems that Peter Ellis won the commission for the first building (Oriel Chambers) as a result of a competition between local architects organized by the developer (an unknown T.A., as the golden initials on top of the main façade declare). The reasons for selecting Ellis’ scheme – from a developer’s perspective - are clear by having a look at the plans and sections. The entrance to the building is located out of the main façade axis because it fronts the corridor, which is located at the axis of the inner part of the building, much longer than the Water Street façade. In other words, internal space efficiency is given much more importance than architectural expression.<br />
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<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/-9-kO3H3w5WI/UdlE6oep38I/AAAAAAAAAvA/eG083Eqktdw/s1600/Alzado+y+planta+Oriel.png" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="436" src="http://2.bp.blogspot.com/-9-kO3H3w5WI/UdlE6oep38I/AAAAAAAAAvA/eG083Eqktdw/s640/Alzado+y+planta+Oriel.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Oriel Chambers: Ground floor plan and elevation to Covent Garden St</td></tr>
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<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/-L2KC8RHcwv8/UdlFNskcy8I/AAAAAAAAAvI/Ogmkjsa0FKA/s1600/Alzados+y+seccion+Oriel.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="364" src="http://1.bp.blogspot.com/-L2KC8RHcwv8/UdlFNskcy8I/AAAAAAAAAvI/Ogmkjsa0FKA/s640/Alzados+y+seccion+Oriel.jpg" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Oriel Chambers: Elevation to Water St, section and elevation to the inner courtyard</td></tr>
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The building from the outside seems to have three main floors but in fact there are five, all with a large amount of natural light and free available space. The central corridor separates the plan in two lettable areas per floor: one side opening to Covent Garden Street and the other side opening to a narrow internal courtyard. Covent Garden Street was not too wide even by 19th century Liverpool standards, so not much light would be expected from the street. But the bit facing the courtyard would be much darker than the other, resulting in a potential loss in let revenues. So a scheme providing lots of light to both sides of the building (external and courtyard’s façade) must have sounded appealing to the owner. And the was right in his selection: the building is still <a href="http://www.bruntwood.co.uk/oriel-chambers/office-space" target="_blank">a lettable space today</a> and it houses the same kind of small firms (barristers among others) with apparent success almost 150 years after it opened.<br />
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<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/-w5-S1zH2u04/UdlFq_Wr_pI/AAAAAAAAAvQ/m3gqxNlXArg/s1600/Office+plan+today.png" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="274" src="http://2.bp.blogspot.com/-w5-S1zH2u04/UdlFq_Wr_pI/AAAAAAAAAvQ/m3gqxNlXArg/s640/Office+plan+today.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Oriel Chambers: proposed occupation in a typical office floor.<br />
The courtyard is the narrow strip located above to the centre-right.<br />
<br /></td></tr>
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<tr><td style="text-align: center;"><a href="http://4.bp.blogspot.com/-ZB94I88c3M8/UdlGK8n3TTI/AAAAAAAAAvY/ICd3i3_QkEM/s1600/Prior_Bolton_Oriel_Window.jpg" imageanchor="1" style="clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="400" src="http://4.bp.blogspot.com/-ZB94I88c3M8/UdlGK8n3TTI/AAAAAAAAAvY/ICd3i3_QkEM/s400/Prior_Bolton_Oriel_Window.jpg" width="300" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Prior Bolton's oriel window at St Bartholomew<br />
the Great church, London c. 1500.<br />
It's interesting to note that the church<br />
was being restored during the 1860s...</td></tr>
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Oriel Chambers was named this way because of the <a href="http://en.wikipedia.org/wiki/Oriel_window" target="_blank">oriel (projecting bay) windows</a> that cover in vertical stripes the two facades. The short façade, seven stripes of windows with the non-symmetrical main entrance, opens to Water Street with a southeast orientation. Water Street was one of the important arteries of the city at the mid-nineteenth century, connecting the City Hall with the Mersey river docks. The lateral northeast façade to Covent Garden Street was by far the largest, extending originally along 20 window strips, divided in five sectors of four vertical bands each. The back half of the building was damaged by German bombs drop over Liverpool during the Second World War, so that now only the first 12 strips are original, and the rest of the volume has been rebuilt in a different style by James & Bywaters in 1959. In fact, the wartime damage enabled the original construction to be fully appreciated regarding its architectural and engineering significance.<br />
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<tr><td style="text-align: center;"><a href="http://4.bp.blogspot.com/-kt9CZXiRR8w/UdlJmfGi4JI/AAAAAAAAAvo/Q0K3y9HV3mk/s1600/05+Oriels+view+2.jpg" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="640" src="http://4.bp.blogspot.com/-kt9CZXiRR8w/UdlJmfGi4JI/AAAAAAAAAvo/Q0K3y9HV3mk/s640/05+Oriels+view+2.jpg" width="480" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Oriels facing Water St.</td></tr>
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The original structure is a combination of cast iron H-shaped columns forming a grid frame with cast iron inverted T-section beams (girders), spanning along the short direction of the building. The shape of the girders comes <a href="http://www.icomos.org/publications/19eisen45.pdf" target="_blank">from other sources</a>; I have verified the columns section on site and they remain as originally. Lateral stiffness is provided by transversal brick walls with chimneys that interrupt the long volume every four stripes. The span between frames is small and it coincides with the windows’ module. This means that the external and internal facades (opening to a large but narrow courtyard) become free of any structural stiffening requirement.<br />
<br />
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<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/-YBP5DeOgHyQ/UdlKHOWXvFI/AAAAAAAAAvw/-bGw_dXAni8/s1600/06+Oriels+view+3.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="480" src="http://2.bp.blogspot.com/-YBP5DeOgHyQ/UdlKHOWXvFI/AAAAAAAAAvw/-bGw_dXAni8/s640/06+Oriels+view+3.jpg" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Oriels facing Covent Garden St. The slim stone column is cladding a cast iron H-shape stanchion.</td></tr>
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<br />
And here is where Peter Ellis started making his magic. The external façades facing Water St and Covent Garden St are covered with oriels: bow windows with an overhang bottom support. Oriels facing Covent Garden St are wider than those facing Water St (see image below); which seems a good idea since the former receive less natural light. The column line between oriels is externally clad with a thin section of stone pieces, reminding slender Gothic columns. These lines don’t end up in arches though, but instead finish rather abruptly – one would say in an abstract way – when they reach the top of the building line. For us the visual result isn’t striking: we are used to building facades resembling rectangular grids. But for Ellis’ contemporaries this façade must have been a clear break in relation to what was considered ‘proper urban architecture’. <br />
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<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/-ejXX0GG9ick/UdlKlvIRBUI/AAAAAAAAAv4/vl5jGnSKq_A/s1600/Oriel+width+comparison.png" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="560" src="http://1.bp.blogspot.com/-ejXX0GG9ick/UdlKlvIRBUI/AAAAAAAAAv4/vl5jGnSKq_A/s640/Oriel+width+comparison.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Oriel width comparison: left to Water St.; right to Covent Garden St.</td></tr>
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The lightness achieved through the oriels is really high by today's standards, and it must have seemed extraordinary to Ellis' contemporaries. The first two images below are inner views of office space overlooking Covent Garden St, and the last one is an image of a narrower window located at the ground floor, with views to Water St.<br />
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<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/-sTu_TRUsUsw/UdlNONS5obI/AAAAAAAAAwI/LFmCOsaGxrg/s1600/11+Oriels+from+inside+1.png" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="634" src="http://2.bp.blogspot.com/-sTu_TRUsUsw/UdlNONS5obI/AAAAAAAAAwI/LFmCOsaGxrg/s640/11+Oriels+from+inside+1.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">View of the oriels from inside. Façade overlooking Covent Garden St.</td></tr>
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<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/-69O3TdIgQ_E/UdlNi5h1iXI/AAAAAAAAAwQ/hr3Sym4w8jA/s1600/12+Oriels+from+inside+2.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="216" src="http://2.bp.blogspot.com/-69O3TdIgQ_E/UdlNi5h1iXI/AAAAAAAAAwQ/hr3Sym4w8jA/s640/12+Oriels+from+inside+2.jpg" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Same as above</td></tr>
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<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/-HS19ZhrZMFo/UdlNsu1mg_I/AAAAAAAAAwY/xr80VKaoMcU/s1600/13+Oriels+from+inside+3.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="640" src="http://3.bp.blogspot.com/-HS19ZhrZMFo/UdlNsu1mg_I/AAAAAAAAAwY/xr80VKaoMcU/s640/13+Oriels+from+inside+3.jpg" width="427" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">View from an oriel towards Water St.</td></tr>
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Air ventilation is obtained via one side-hung window at every oriel. The height of the window is 1/2 the height of the oriel, so they can be read as vertical sliding openings, which they are not. The sash opens to the inside and the sash retainer is visible from the outside. See details here below.<br />
<div>
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="http://4.bp.blogspot.com/-ww3aCGJ2u7E/UdlOB9SZNFI/AAAAAAAAAwg/6odkqGzxg2s/s1600/Oriel+detail+1.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="640" src="http://4.bp.blogspot.com/-ww3aCGJ2u7E/UdlOB9SZNFI/AAAAAAAAAwg/6odkqGzxg2s/s640/Oriel+detail+1.jpg" width="434" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Side hung window, opening to the inside. Notice the bottom hinge.</td></tr>
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<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/-QfcLXueV_5o/UdlQBzMAtwI/AAAAAAAAAww/J3dcQb8en5A/s1600/Oriel+detail+2.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="480" src="http://3.bp.blogspot.com/-QfcLXueV_5o/UdlQBzMAtwI/AAAAAAAAAww/J3dcQb8en5A/s640/Oriel+detail+2.jpg" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Sash retainer located outside the window. The sash can be locked in three positions.</td></tr>
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<br />
<b>The (hidden) curtail wall in Oriel Chambers</b><br />
Now, glazed as it looks, how could this be the first curtain wall in a multi-storey building in history? This is not the case if you focus on the external facades only: the amount of glass is noticeable but what we see is a continuum of large projecting glass elements in a rectangular grid of stone blocks cladding an iron frame.<br />
<br />
There is at least a previous building in Glasgow that could claim precedent, the <a href="http://canmore.rcahms.gov.uk/en/site/44140/details/glasgow+36+jamaica+street+gardner+s+warehouse/" target="_blank">Gardner’s Warehouse in 36 Jamaica Street</a> (see below), built in 1856 by John Baird using a structural system patented by R. McConnell, iron founder. The Gardner’s façade reminds the Crystal Palace, built in London in 1851, in a more direct way than Peter Ellis’ one. The building in Glasgow was a warehouse after all, ours is an office building located in prime location in Liverpool. <br />
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/-ddUFXtuanLU/UdlRhcpkNMI/AAAAAAAAAxA/K0rC1eRpc3I/s1600/Gardner's+warehouse+glasgow+01.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="498" src="http://3.bp.blogspot.com/-ddUFXtuanLU/UdlRhcpkNMI/AAAAAAAAAxA/K0rC1eRpc3I/s640/Gardner's+warehouse+glasgow+01.jpg" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Gardner's Warehouse. 36 Jamaica St, Glasgow. John Baird 1856.</td></tr>
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The real secret of Oriel Chambers is hidden behind; at it becomes visible only when you are given access to the inner courtyard. My colleague Maurits and I were lucky to arrive to the building on a workday morning at 9am, when clerks were entering their offices. Looking like an architect has advantages if you want to access a private property, and we were soon taken to the courtyard through the solicitor’s firm occupying the main floor.<br />
<br />
There came the surprise: a receding, all-glass façade with a shape of protruding elements between columns seemed to absorb any little ray of light arriving to the courtyard. Again, an architectural solution that seems contemporary to us but absolutely new at the time of its design. One may say that the oriel glass boxes at the front are the ‘culturized’ version of this completely ‘form follows function’ glazed solution at the back.<br />
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/-pKZN5Gb_gbA/UdlZWf3ZBgI/AAAAAAAAAxc/DrberqgYqio/s1600/16+Courtyard+1+and+section.png" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="560" src="http://1.bp.blogspot.com/-pKZN5Gb_gbA/UdlZWf3ZBgI/AAAAAAAAAxc/DrberqgYqio/s640/16+Courtyard+1+and+section.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Left: view of Oriel Chambers inner courtyard. Right: vertical section of the curtain wall opening to the courtyard. Notice the cast iron vertical stanchion and how the curtain wall moves out of it every floor down.</td></tr>
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Look at the vertical section above right and you will get it: each floor recedes a bit over the one below to allow for more light coming to the bottom. The sloped rooftop piece above the windows at each level is made of wired glass to obtain direct solar radiation. A counter-sloped panel acts as bottom parapet, and it looks like a thin piece of timber with an external bituminous layer. The iron H-shaped columns are not at the receding façade line but in a vertical axis independent from it. The glazed wall acts as a thin, lightweight layer gently cladding a structure, not taking any load but its own, with a shape that bows to light and brings it in without losing a bit. That's a mature curtain wall in concept.<br />
<br />
Since there are very few images of this extraordinary piece or architecture in the Web, I am adding here below a selection of the pictures I took during our early morning visit.<br />
<br />
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<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/--JuiluDoHec/UdlcC0W2p8I/AAAAAAAAAx8/NtSJLyVxlpk/s1600/17+Courtyard+2.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="640" src="http://2.bp.blogspot.com/--JuiluDoHec/UdlcC0W2p8I/AAAAAAAAAx8/NtSJLyVxlpk/s640/17+Courtyard+2.jpg" width="480" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">General view of the courtyard. All structural members of the curtain wall are in timber.</td></tr>
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/-bB7bPT0iFxs/UdlcXWQLyuI/AAAAAAAAAyE/lhgRDe9CMrI/s1600/18+Courtyard+3.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="640" src="http://2.bp.blogspot.com/-bB7bPT0iFxs/UdlcXWQLyuI/AAAAAAAAAyE/lhgRDe9CMrI/s640/18+Courtyard+3.jpg" width="480" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">The top and vertical members are in glass; the bottom one is a timber panel.</td></tr>
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/-Tx_U-fJUqIo/Udlak57sRzI/AAAAAAAAAxw/8PXdC59c3NU/s1600/19+Courtyard+4.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="640" src="http://2.bp.blogspot.com/-Tx_U-fJUqIo/Udlak57sRzI/AAAAAAAAAxw/8PXdC59c3NU/s640/19+Courtyard+4.jpg" width="480" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Detail of the curtain wall, floors one to three (4th floor is flat vertical)</td></tr>
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<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/-OOxBQfwsmTE/Udlc-2lh-vI/AAAAAAAAAyQ/6SPKh3heSmc/s1600/20+Courtyard+6.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="640" src="http://3.bp.blogspot.com/-OOxBQfwsmTE/Udlc-2lh-vI/AAAAAAAAAyQ/6SPKh3heSmc/s640/20+Courtyard+6.jpg" width="480" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Contrast between the curtain wall and the receding structural wall to the left.</td></tr>
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<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/-I066JFzINp0/UdldPseIDhI/AAAAAAAAAyY/5G9bIfqdJ3o/s1600/21+Courtyard+8.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="640" src="http://3.bp.blogspot.com/-I066JFzINp0/UdldPseIDhI/AAAAAAAAAyY/5G9bIfqdJ3o/s640/21+Courtyard+8.jpg" width="480" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Corner of the curtain wall at the edge of the courtyard. The narrow strip is located opposite to Water St.</td></tr>
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<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/-a1mZJWPAwD4/Udldk5oP2kI/AAAAAAAAAyg/zzlr9yhWj0A/s1600/22+Courtyard+9.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="640" src="http://1.bp.blogspot.com/-a1mZJWPAwD4/Udldk5oP2kI/AAAAAAAAAyg/zzlr9yhWj0A/s640/22+Courtyard+9.jpg" width="480" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Corner of the curtain wall looking up. Note the receding structural wall in the centre.</td></tr>
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<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/-ej0wXSvGlP0/Udld1EG67pI/AAAAAAAAAyo/JYC7I7cNFp0/s1600/23+Courtyard+10.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="640" src="http://2.bp.blogspot.com/-ej0wXSvGlP0/Udld1EG67pI/AAAAAAAAAyo/JYC7I7cNFp0/s640/23+Courtyard+10.jpg" width="480" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Connection between the curtain wall and the receding brick wall. The building to the left is the bombarded wing that was re-built after the war.</td></tr>
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/-UqpLfkrghj8/UdleUl9ALwI/AAAAAAAAAyw/6XZGIMsNmf0/s1600/24+Courtyard+11.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="640" src="http://2.bp.blogspot.com/-UqpLfkrghj8/UdleUl9ALwI/AAAAAAAAAyw/6XZGIMsNmf0/s640/24+Courtyard+11.jpg" width="480" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Detail of the above. The sloped glass on top is very visible.</td></tr>
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<tr><td style="text-align: center;"><a href="http://4.bp.blogspot.com/-IK7K7CnArMA/UdleijdPs6I/AAAAAAAAAy4/eqJRXo2I-Ho/s1600/25+Oriel+to+courtyard.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="640" src="http://4.bp.blogspot.com/-IK7K7CnArMA/UdleijdPs6I/AAAAAAAAAy4/eqJRXo2I-Ho/s640/25+Oriel+to+courtyard.jpg" width="460" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">View of the curtain wall to the courtyard from inside. See the sloped glass on top.</td></tr>
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<br />
This is clearly a proto-20th century office building curtain wall, thirty years older than those of the Chicago School but going far beyond them and connecting directly with Gropius’ Fagus Factory in Alfeld – which was to be built fifty years later! Now is when you grasp the importance of this hidden place.<br />
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<b>16 Cook Street – more news to come </b><br />
After the successful visit to Oriels Chambers Maurits and I walked to Cook Street, located less than ten minutes away, also at the city centre. 16 Cook Street is another rental office building, smaller than the previous one, that Peter Ellis finished in 1866. I have not found any information about the owner. Was it the same developer from Water Street or a different one? Was this building the result of a competition or a direct commission? Judging by its smaller dimensions and the use of very similar architectural features I tend to think that this was a direct commission, for a client who knew well what he wanted.<br />
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The building plan is an L-shape (as Oriel Chambers) but much smaller in size and with only a main façade. The rear and lateral walls open to a courtyard that was as narrow as the former.</div>
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<tr><td style="text-align: center;"><a href="http://4.bp.blogspot.com/-PfTDVbQBxMs/UdmmVBx9z0I/AAAAAAAAAzI/lsnJAfFzSVw/s1600/27+Top+of+front+view.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="468" src="http://4.bp.blogspot.com/-PfTDVbQBxMs/UdmmVBx9z0I/AAAAAAAAAzI/lsnJAfFzSVw/s640/27+Top+of+front+view.jpg" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">16 Cook Street, top of front view</td></tr>
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<tr><td style="text-align: center;"><a href="http://4.bp.blogspot.com/-of0AfureP9c/UdmmjT1SxxI/AAAAAAAAAzQ/HJM0TTb92nk/s1600/28+Contrast+with+neighbour.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="480" src="http://4.bp.blogspot.com/-of0AfureP9c/UdmmjT1SxxI/AAAAAAAAAzQ/HJM0TTb92nk/s640/28+Contrast+with+neighbour.jpg" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Contrast with contemporary neightbour facade</td></tr>
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Again, you can find some references in today's architectural literature to the main façade but very few to the rear one. The façade to Cook St is perfectly symmetrical. The play between glass and stone appears again, but here there are no oriels: glass remains flat between slender stone-clad columns. The whole can be read as an abstract gothic- or Venetian-like window: a central, three-strips bay ends in an arch at the top and is flanked by two smaller vertical bays, also ending in smaller arches. The building, as that in Water St, has five floors, but here all floors are fairly the same height and express themselves similarly to the façade. Verticality together with light-catching seems to be the theme for Peter Ellis here.<br />
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The entrance to the building is located at the left corner, with the shop entrance conveniently symmetrical at the right end. The entrance hall is a slender corridor connecting the street with a spiral staircase that opens to the back courtyard, clad almost entirely in glass with the thinnest of cast iron mullions.<br />
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/-SHT1crGeDTk/Udmn_FprpKI/AAAAAAAAAzs/qX0Z7CoxtYI/s1600/31+Back+elevation+and+spiral+stairs.png" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="540" src="http://3.bp.blogspot.com/-SHT1crGeDTk/Udmn_FprpKI/AAAAAAAAAzs/qX0Z7CoxtYI/s640/31+Back+elevation+and+spiral+stairs.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">16 Cook St: back elevation (left) and spiral stairs from the courtyard (right)</td></tr>
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<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/-4ckYILxasSg/UdmoW9qY1LI/AAAAAAAAAz0/BGFvN09DLdE/s1600/33+Spiral+stair+from+inside.png" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="412" src="http://2.bp.blogspot.com/-4ckYILxasSg/UdmoW9qY1LI/AAAAAAAAAz0/BGFvN09DLdE/s640/33+Spiral+stair+from+inside.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Spiral stair from inside</td></tr>
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The stair and its cladding are supported from both sides at every floor, leaving the impression that the whole is floating without any column. Clever but not so difficult considering its tiny dimensions. This leaves the rest of the plan available for one or two offices per floor, with plenty of light entering through the street and/or the rear courtyard windows.<br />
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<tr><td style="text-align: center;"><a href="http://4.bp.blogspot.com/-0LGHS9VxmV0/UdmnPVHTPrI/AAAAAAAAAzc/9qq0wTxXjF0/s1600/29+ABW+Architects+inside+space.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="480" src="http://4.bp.blogspot.com/-0LGHS9VxmV0/UdmnPVHTPrI/AAAAAAAAAzc/9qq0wTxXjF0/s640/29+ABW+Architects+inside+space.jpg" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">The façade as seen from ABW Architects office</td></tr>
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Maurits and I were lucky once again. The second floor is at present occupied by <a href="http://www.abwarchitects.co.uk/" target="_blank">ABW Architects</a>, a firm formed in 2008 by two partners, Simon Almond and Andrew Brown, working across the northwest UK. We were given access to their studio and could have a chat and take pictures. The atmosphere inside was great – lots of light but definitely a small space. Old Peter Ellis was clever enough to conceal the limited available space playing with a continuous volume that seems much larger from the street. <br />
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right; margin-left: 1em; text-align: right;"><tbody>
<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/-J0lQ4KgJ7pk/UdmncEd1bvI/AAAAAAAAAzk/vANUucU0fg0/s1600/30+ABW+Architects-image.asp.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="640" src="http://1.bp.blogspot.com/-J0lQ4KgJ7pk/UdmncEd1bvI/AAAAAAAAAzk/vANUucU0fg0/s640/30+ABW+Architects-image.asp.jpg" width="587" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Drawing from inside the office (from ABW Architects webpage)</td></tr>
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And again a curtain wall surprise was waiting for us there. It was not visible in the front façade, glazed as it is. Only when you access the office floors you perceive the small courtyard and the way the building opens to it at the back in search of light.<br />
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/--fonzxzljmU/UdmoslYx74I/AAAAAAAAAz8/_8-gx5mu3Yw/s1600/32+Back+curtain+wall+from+the+stairs.png" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="438" src="http://1.bp.blogspot.com/--fonzxzljmU/UdmoslYx74I/AAAAAAAAAz8/_8-gx5mu3Yw/s640/32+Back+curtain+wall+from+the+stairs.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Back curtain wall as seen from the stairs</td></tr>
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Here the façade to the courtyard is not receding back as it moves up, probably because of the lack of space. But we find again the lightweight, protruding curtain wall in three planes: vertical and sloped with glass, counter sloped with a timber panel. And this time the curtain wall ends in a transparent corner at the very back of the building.<br />
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We saw two H-shaped columns completely independent from the wall. One of them shows how the curtain wall is attached to the cast iron structure using an iron strip in tension (see bottom image left).<br />
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/-aXLiSjiRxxM/Udmo8WsePeI/AAAAAAAAA0E/CZBv6YLs2Tc/s1600/35+Inner+cast+iron+column+and+curtain+wall.png" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="412" src="http://3.bp.blogspot.com/-aXLiSjiRxxM/Udmo8WsePeI/AAAAAAAAA0E/CZBv6YLs2Tc/s640/35+Inner+cast+iron+column+and+curtain+wall.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Inner cast iron column at the back office and curtain wall connection</td></tr>
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<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/-PkcmiWdsaBs/UdmpQkB_pyI/AAAAAAAAA0M/hOyZAF1Q_pE/s1600/36+Corner+glass+around+cast+iron+column.jpg" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="640" src="http://3.bp.blogspot.com/-PkcmiWdsaBs/UdmpQkB_pyI/AAAAAAAAA0M/hOyZAF1Q_pE/s640/36+Corner+glass+around+cast+iron+column.jpg" width="411" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Corner glass around cast iron column</td></tr>
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The other column at the back corner is even more striking, because the glass wall completely clads the column from the outside without touching the structure. We have seen this detail many times in modern curtain wall architecture, but in 1866?<br />
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The contact of the curtain wall horizontal stripes with the vertical glazed cylindrical staircase takes place in a clean way. It could be a Dutch architectural detail from the 1930s. An amazing solution but concealed from everyone’s view – as much today as when it was built.<br />
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/-VCTl49Xy8O0/UdmplWlI6xI/AAAAAAAAA0U/jEQGgKCkiOw/s1600/37+Corner+glass+around+cast+iron+column+details.png" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="410" src="http://2.bp.blogspot.com/-VCTl49Xy8O0/UdmplWlI6xI/AAAAAAAAA0U/jEQGgKCkiOw/s640/37+Corner+glass+around+cast+iron+column+details.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Details of the curtain wall around the corner cast iron column</td></tr>
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<b><br /></b>
<b>Reaction to the two Ellis’ buildings </b><br />
Seen from today’s perspective Oriel Chambers and 16 Cook Street may be seen as a precedent and even a paradigm of the Modern Movement - but it was not one immediately appreciated to say the least. Oriel Chambers was seen, for the local Porcupine, as ‘hard, liney, and meagre’. The strongest critic by far came from the London architectural periodical The Building News in February 7, 1868, signed by a ‘our own correspondent’. The critic pompously dismissed Oriel Chambers out of hand: <br />
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<i>This is a kind of greenhouse architecture run mad; consisting of a series of vertical bays running completely from top to bottom of the building (…) rising from the plinth without any basis, said shafts being flanked by a very large coarse “nail head” ornament. (…) The style, in short, might be described as “lunar Gothic;” and no one who has not seen it would believe, we think, that such a thing could, in the present day, be erected in cold blood by any person calling himself a member of the architectural profession. </i><br />
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In a similar vein, The Builder stated: <br />
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<i>The plainest brick warehouse in town is infinitely superior as a building to that meager agglomeration of protruding plate-glass bubbles in Water Street termed Oriel Chambers. Did we not see this vast abortion (which would be depressing were it not ludicrous) with our own eyes; we should have doubted the possibility of its existence. Where and in what are their beauties supposed to lie? </i><br />
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As late as 1921, Charles Reilly, head of the Liverpool School of Architecture, called it the ‘oddest building in Liverpool, at once so logical and so disagreeable … as a cellular habitation for the human insect is a distinct asset to the town’.<br />
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<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right; margin-left: 1em; text-align: right;"><tbody>
<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/-JPIohORCTTQ/Udmr_TNKVaI/AAAAAAAAA08/3e5HKFsZoGM/s1600/Oriel+during+the+war.jpg" imageanchor="1" style="clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="640" src="http://3.bp.blogspot.com/-JPIohORCTTQ/Udmr_TNKVaI/AAAAAAAAA08/3e5HKFsZoGM/s640/Oriel+during+the+war.jpg" width="624" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Oriel Chambers' glass windows protected during the Second World War</td></tr>
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It is clear now that those radical cast iron frames that Glasgow, Manchester, and Liverpool produced among others in the 1860s and 70s, led after the 1870s to a slow falling-away from industrial innovation and to a shift back to London-supported historicist decorations. Probably this was the origin not only to the decline of the North but also to British near-absence from the Modern Movement up to very late in the twentieth century.<br />
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The positive reaction produced by the two Ellis' buildings, although little, was not completely inexistent in 20th century British architecture. As Brian Hutton wrote in Architectural Review in 2008:<br />
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<div>
<i>Perhaps Oriel displeased locals because it abstracted from a Gothic model in a city that remained mostly Classical. (…) And indeed, to eyes now less Modern than Post-Modern, what may strike from the Oriel is less a paradigm of rationality than something both more abstract and more wilful. So that when, in the 1960s, James Stirling drew from Oriel in his Leicester Engineering Laboratory, his model was neither its chamfered details nor even its functionalism, but the geometric glass cascade of its atrium walls. </i><br />
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James Stirling, although born in Glasgow, grew up in Liverpool and studied architecture there.<br />
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Adam Caruso (from Caruso St John) is a contemporary architect with a strong personal link to the two Ellis buildings. <a href="http://www.bdonline.co.uk/buildings/adam-caruso-on-the-impact-of-liverpool%E2%80%99s-pioneering-ellis-buildings/3155796.article" target="_blank">He wrote in 2010</a>: </div>
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<div>
<i>I’m not so interested in the Ellis buildings being examples of a proto-modernism, a part of that inexorable linear progression from the Crystal Palace to European inter-war modernism. I think that’s a convenient post-rationalisation perpetuated by modernist historians. I am more interested in the Ellis buildings in the context of the cast-iron offices and warehouses that were being built in the mid-19th century in Liverpool and Glasgow, like the Gardner’s Warehouse in Glasgow by John Baird in 1856. These buildings had cast-iron structures and facades and had all but eliminated most of the elements of what would have previously constituted a “correct” urban facade. I am particularly interested in why Peter Ellis chose to clad his cast-iron structures in stone,organised according to a Gothic language (…). He was developing an expression for his building that was in addition to, and was autonomous of, their technology.</i><br />
<b><br /></b><b>Peter Ellis, John Root and curtain walls </b><br />
Can we spot an influence of Peter Ellis’ two proto-modern curtain walls in any later period of architecture? As Adam Caruso mentioned above, it is almost impossible to trace any linear progression from the Crystal Palace to the glazed boxes of the 1930s passing through Peter Ellis. A potential link might be the application of glass and iron frame technology to the front of urban buildings, almost for the first time in history. But many years had to pass before large glass plates and iron / steel frames could come back to the front. <br />
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An interesting side influence, though not too obvious, has been established between our two buildings and the architectural training of John Wellborn Root (1850 – 1891), who would become the partner in the Chicagoan firm Burnham & Root, one of the founders of the Chicago School around the 1880s and 90s. Root was born in Georgia and raised in Atlanta with his parents. In 1864, when Atlanta fell to the Union during the American Civil War, Root’s father managed to send him with two brothers on a steamer to Liverpool, where John’s father had shipping business contacts. While in Liverpool, Root studied at a school in Claremont for three years (from 14 to 17 years old), and he even passed the exams for entering Oxford. But in 1867 he returned to the US to study architecture at New York University. <br />
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It can only be a speculation, but a teen-aged John Root might have seen and remembered the brand new Oriel Chambers in Liverpool, together with the spiral staircase of 16 Cook St, the latter finished just months before he sailed back to America. Now fast forward to the 10 floor-high Rookery building in Chicago, built in 1888, one of Root’s masterpieces. Can you see a vague influence from Oriel at the top corner stone pinnacles?<br />
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/-UtCS4rU3QvM/Udmqnr2gRqI/AAAAAAAAA0k/66hdxDiWchA/s1600/1891_Rookery_building.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="510" src="http://1.bp.blogspot.com/-UtCS4rU3QvM/Udmqnr2gRqI/AAAAAAAAA0k/66hdxDiWchA/s640/1891_Rookery_building.jpg" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">The Rookery Building Chicago, 1888. Burnham and Root architects.</td></tr>
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There are no oriel windows here, except maybe the gentle curvature of the central bay of windows up to the sixth floor...<br />
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<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://4.bp.blogspot.com/-NUlvtrlTilU/Udmq4iCo7YI/AAAAAAAAA0s/cYINeCkNIfU/s1600/1891_Rookery+atrium.jpg" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="640" src="http://4.bp.blogspot.com/-NUlvtrlTilU/Udmq4iCo7YI/AAAAAAAAA0s/cYINeCkNIfU/s640/1891_Rookery+atrium.jpg" width="508" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">The Rookery building Chicago, 1888. Spiral staircase at the inner atrium</td></tr>
</tbody></table>
Perhaps the clearest reminiscence, once again, does not take place at the front but in the courtyard above the glazed atrium. Here yes, the spiral staircase in the centre is in a similar vein to Ellis’ model in Cook Street, and the window-to-wall ratio of the inner façades reminds that of the two courtyards back in Liverpool.<br />
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<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right; margin-left: 1em; text-align: right;"><tbody>
<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/-AMTfW-2DUko/UdmsWEDDwDI/AAAAAAAAA1E/Q3Y8o348o8M/s1600/Stone+text+at+the+door.jpg" imageanchor="1" style="clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="640" src="http://1.bp.blogspot.com/-AMTfW-2DUko/UdmsWEDDwDI/AAAAAAAAA1E/Q3Y8o348o8M/s640/Stone+text+at+the+door.jpg" width="452" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Engraved plate at the door of Oriel Chambers</td></tr>
</tbody></table>
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What happened with Peter Ellis after his two office buildings were finished (and received with derision in Liverpool and London)? We have no idea: he seems to have come back to surveying or to civil engineering, but there are no traces of his activities at all. There are no buildings signed by Ellis after 1866, so it seems quite obvious that the sharp criticism ended with his short architectural career. The last news is that of his death in 1884, at the long age of 80 years. His obituary appeared in the Liverpool Daily Post in October 21.<br />
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It is an irony to see that Peter Ellis is remembered (in a stone engraved plate by the door to Oriel Chambers, see above) as a '<i>pioneer in the use of prefabricated structural units in cast iron</i>'. This, being true, is unfair to his evident contribution as a forefather of curtain walling, clearly his largest achievement and the one by which he is and will be remembered. Sometimes two buildings are enough to have your name written in history.</div>
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Ignacio Fernández Sollahttp://www.blogger.com/profile/03918193520738485621noreply@blogger.com11314 Water Street, Liverpool, Merseyside L2 8TD, Reino Unido53.406436 -2.993516999999997127.8844015 -44.302111 78.9284705 38.315077tag:blogger.com,1999:blog-1298203288964657974.post-78554551630662655622012-06-30T23:29:00.002+02:002012-07-04T06:50:47.398+02:00Acoustic properties of glass: not so simple<div>
At Arup, working with different specialists creates many opportunities to learn from each other. Sometimes one forgets that engineers who know everything about dark matters as climatic loads in glass or intricacies of structural silicone may not have a clue about the acoustic performance of a window.<br />
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That's why these questions keep coming to my desk (remember I'm an incurable generalist in the façades world): what effect does glass thickness have in the acoustics of a double glass unit? Or what matters more in the acoustical performance of insulated glass: the thickness in a monolithic pane, the effect of lamination or the dimension of the cavity? Here you will find some graphical answers to these questions. As usual a number of hidden surprises will come out from the data mining.<br />
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<a href="http://4.bp.blogspot.com/-wt5-4P8tlPQ/T-8hDC2c90I/AAAAAAAAArQ/2GF5wZ5dA1g/s1600/white-noise.jpg" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="162" src="http://4.bp.blogspot.com/-wt5-4P8tlPQ/T-8hDC2c90I/AAAAAAAAArQ/2GF5wZ5dA1g/s640/white-noise.jpg" width="640" /></a></div>
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Let us start by reviewing two concepts that are paramount to measuring glass performance against noise: <i>loudness</i> (in particular sound pressure level, the decibels thing) and <i>frequency</i> (the Hertz, not related to car rental)<br />
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<h4>
<b>1/ Loudness: sound intensity, sound pressure and sound pressure level</b></h4>
<h4>
<span class="Apple-style-span" style="font-weight: normal;">From physics to applied acoustics in buildings. No pain, promised. Loudness is an intuitive concept: a loud noise usually has a larger pressure variation and a weak one has a smaller pressure variation. Depending on what we are looking for - the cause, the effect or the perception of noise - we use different variables and units:</span></h4>
<ul>
<li><i>Sound intensity</i> refers to the <u>cause</u> of noise (not of our concern, only of interest for acusticians). It measures energy flow at the source, so its unit is W/m2.</li>
<li><i>Sound pressure</i> refers to the <u>effect</u> of noise as a wave impacting any given surface, that is, noise as energy being transfered through air. Not of our concern either, more for physicists. Its unit is the Pascal or N/m2 (1Pa = 1N/m2). </li>
<li><i>Sound pressure level</i> or SPL (here comes the fun) refers to the <u>perception</u> of noise in humans as it can be "read" by our ears. So SPL is what matters to us, poor construction buddies. For ease of numbering SPL is measured in decibels (dB). A dB is a dimensionless unit used to express logarithmically the ratio of a value (the measured sound pressure) to a reference value (the lower threshold of hearing). Decibels are used since sound pressure level expressed in Pa would be too wide. 0 dB (the lower threshold of audition for humans) equals 0,00002 Pa; whilst 140 dB (the upper human threshold or threshold of pain) equals 200 Pa. This is a range of 140 against 10 million. But logarithms are not "natural" to understand, so some examples will be of help.</li>
</ul>
Sound intensity, sound pressure and sound pressure level are obviously related, but they measure different things and they should not be confused. The table below, taken from the very useful <a href="http://www.sengpielaudio.com/calculator-soundlevel.htm" target="_blank">Sengpiel audio webpage</a> provides some tips for getting it right, at least conceptually:<br />
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<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/-hdQh8nOuZ7Q/T-7EgkzZtvI/AAAAAAAAAqE/XY1hD1cjIz4/s1600/Imagen+1.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="400" src="http://2.bp.blogspot.com/-hdQh8nOuZ7Q/T-7EgkzZtvI/AAAAAAAAAqE/XY1hD1cjIz4/s640/Imagen+1.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">SPL variation (left column) related to sound pressure (field quantity) and sound intensity (energy quantity)</td></tr>
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Lessons from the table above:</div>
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<ul>
<li>A raise in sound pressure level (SPL) of 3 dB equals an increase in sound pressure (field quantity) of 1.414 times, and (everything else being equal) it comes as a result of doubling the sound intensity (the source of sound).</li>
<li>A reduction in sound pressure level measured inside a room of 10 dB equals a reduction in sound pressure of 3.16 times, and it comes as a result of dividing the sound intensity (noise generated on the outside) by ten.</li>
</ul>
A typical opaque façade (not glass) can have a sound reduction index (a reduction of SPL) of around 40 dB. This means that if the SPL measured at the street is 70 dB, inside the façade one would perceive only 30 dB. Up to here, just arithmetic. </div>
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Now, if the sound reduction index of the façade could be raised from 40 to 43 dB, the perceived noise coming from the street would equal that of reducing the source of noise by half. Even more, if the façade could be acoustically improved so that its sound reduction index raised from 40 to 50 dB (difficult but it can be done), the perceived noise coming from the street would equal that of reducing the source of noise (sound intensity) by ten: ten times less cars in the street, ten times less people celebrating the victory of their football team outside.</div>
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<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/-H8WI4UhYCA0/T-8eEw3ZplI/AAAAAAAAArE/bHa2xSECwnY/s1600/Imagen+5.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="410" src="http://3.bp.blogspot.com/-H8WI4UhYCA0/T-8eEw3ZplI/AAAAAAAAArE/bHa2xSECwnY/s640/Imagen+5.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Expected sound pressure levels for different noises and their equivalent sound pressure and sound intensity. Source: <a href="http://www.sengpielaudio.com/TableOfSoundPressureLevels.htm" target="_blank">Sengpiel Audio</a>.</td></tr>
</tbody></table>
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We got the point: sound pressure level measured in dB (sometimes indicated as dB-SPL) is critical for architectural physics - a small variation can make a lot of difference. But loudness (sound expressed as pressure variation) is not the only story. Noise - what we want to avoid inside our buildings - is the mixture of sounds of different "quality", some are bass, some are treble. Is our façade or our glass pane capable of stopping each of these "noise qualities" in the same percentage? Could an envelope act as a barrier for bass and a filter for treble? What do bass and treble have to do with noise?</div>
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<h4>
<b>2/ Frequency of sound</b></h4>
<div>
Sound is the quickly varying pressure wave travelling through a medium. When sound travels through air, the atmospheric pressure varies periodically (it kind of vibrates). The number of pressure variations per second is called the frequency of sound, and it is measured in Hertz (Hz) which is defined as the number of cycles per second.</div>
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<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://4.bp.blogspot.com/-BXCP-r7cbzI/T-7tjpOy2mI/AAAAAAAAAqQ/vLjXuDbAHsc/s1600/Amplitude-sound+waves.gif" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="454" src="http://4.bp.blogspot.com/-BXCP-r7cbzI/T-7tjpOy2mI/AAAAAAAAAqQ/vLjXuDbAHsc/s640/Amplitude-sound+waves.gif" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span class="Apple-style-span" style="line-height: 24px;"><span class="Apple-style-span" style="font-size: x-small;">Graphic representations of a sound wave. (A) Air at equilibrium, in the absence of a sound wave; (B) compressions and rarefactions that constitute a sound wave; (C) transverse representation of the wave, showing amplitude (A) and wavelength (λ). Source: Encyclopaedia Britannica.</span></span></td></tr>
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<span class="Apple-style-span" style="color: #444444; font-family: 'Open Sans', sans-serif;"><span class="Apple-style-span" style="font-size: 13px; line-height: 15px;"><i><br /></i></span></span><span class="Apple-style-span" style="font-size: 14px;"><span class="Apple-style-span" style="color: #444444; font-family: 'Open Sans', sans-serif; font-size: 13px; line-height: 15px;"></span></span></div>
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The higher the frequency, the more high-pitched a sound is perceived. Sounds produced by drums have much lower frequencies than those produced by a whistle.</div>
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The unit of frequency is the Hertz (Hz). For a sound vibration to be audible to human beings the object must vibrate between 20 and 20,000 times per second. In other words the audible sound has a frequency of between 20 and 20,000 Hz.</div>
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High-pitched sounds (treble) have a frequency much greater than bass sounds. The treble frequency ranges between 2,000 and 4,000 Hz while the bass range from 125 to 250 Hz. </div>
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<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/-9O85Lf-vLuI/T-7uV6hMb8I/AAAAAAAAAqY/O2QJaHM1PAg/s1600/loudness+and+frequency+of+sound.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="374" src="http://3.bp.blogspot.com/-9O85Lf-vLuI/T-7uV6hMb8I/AAAAAAAAAqY/O2QJaHM1PAg/s640/loudness+and+frequency+of+sound.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Above: measure of loudness (wave height). The higher the louder.<br />
Below: measure of frequency (wave length). Bass sound has long waves, treble has short waves.</td></tr>
</tbody></table>
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Bad news: frequency and loudness are interrelated in the human ear. The range of 20 Hz to 20,000 Hz is called the audible frequency range - we know this already. But the sounds we hear are a mixture of various frequencies, and <u>we don't perceive all of them with the same clarity</u>. Let's see what the implication of this is.<br />
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The entire audible frequency range can be divided into 8 or 24 frequency bands known as octave bands or 1/3 octave bands respectively for analysis. An octave band is the band of frequencies in which the upper limit of the band is twice the frequency of the lower limit. Any particular sound or noise can be represented as a number of 8 (or 24) sound pressure levels in the frequency bands, as illustrated by the diagram below.<br />
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/-gOZFzNfg3oQ/T-7vjTXu__I/AAAAAAAAAqo/jB4SguaLB5g/s1600/Imagen+2.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="404" src="http://3.bp.blogspot.com/-gOZFzNfg3oQ/T-7vjTXu__I/AAAAAAAAAqo/jB4SguaLB5g/s640/Imagen+2.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">A real sound shown as a combination of different sound presure levels, one per each of the 24 frequency bands. Column width: 1/3 octave band (24 in total). Column height: SLP at each frecuency band, measured in dB.</td></tr>
</tbody></table>
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The response of the human ear to sound is dependent on the frequency of the sound. The human ear has its peak response around 2,500 to 3,000 Hz and has a relatively low response at low frequencies. Hence, the single sound pressure level obtained by simply adding the contribution from all 1/3 octave bands together will not correlate well with the non-linear frequency response of the human ear.<br />
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This has led to the concept of weighting scales. The following diagram shows the "A-weighting" scale:</div>
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/-JMGrDFoEutE/T-7xTp_inQI/AAAAAAAAAqw/yxUXPSC37n0/s1600/Imagen+3.png" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="548" src="http://1.bp.blogspot.com/-JMGrDFoEutE/T-7xTp_inQI/AAAAAAAAAqw/yxUXPSC37n0/s640/Imagen+3.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Reduction of SPL (in dB) at frequencies below and above 2000 to 3000 Hz to reflect the frequency response of the human ear.</td></tr>
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<div>
In the "A-weighting" scale, the sound pressure levels for the lower frequency bands and high frequency bands are reduced by certain amounts before they are being combined together to give one single sound pressure level value. This value is designated as dB(A). The dB(A) is often used as it reflects more accurately the frequency response of the human ear. </div>
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<div>
Other, less used weighting scales, are dB(B) and dB(C). The decibel C filter is practically linear over several octaves and is suitable for subjective measurements at very high sound pressure levels. The decibel B filter is between C and A. The three filters are compared below:</div>
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<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://4.bp.blogspot.com/-c1Bbrn6tNoo/T-8b-QWICmI/AAAAAAAAAq8/1E3hkdtm9lo/s1600/Imagen+4.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="126" src="http://4.bp.blogspot.com/-c1Bbrn6tNoo/T-8b-QWICmI/AAAAAAAAAq8/1E3hkdtm9lo/s640/Imagen+4.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Noise filtering at different octaves of frequency applying decibel filter scales A, B or C.</td></tr>
</tbody></table>
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That was enough for theory. Let us now see how all this affects the performance of glass as a real acoustic barrier.<br />
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The four hand-sketched graphs shown here below are all taken from the first edition of a great book called "<a href="http://books.google.es/books?id=qY8eR0GraqEC&printsec=frontcover&hl=es#v=onepage&q&f=false" target="_blank">Detailing for acoustics</a>", written by Peter Lord and Duncan Templeton. There are three editions by now and I highly recommend buying one if you are an architect interested in acoustic issues applied to buildings.</div>
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<h4>
<b>3/ Glass thickness effect</b></h4>
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<div>
The sound attenuation of any material depends on its mass, stiffness and damping characteristics. With a single glass pane the only effective way to increase its performance is to increase the thickness, because stiffness and damping cannot be changed. The sound transmission loss for a single glass pane, measured over a range of frequencies, varies depending on glass thickness.<br />
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Thicker glass tends to provide greater sound reduction even though it may actually transmit more sound at specific frequencies. Every glass pane thickness has a weak frequency value; that is, a frequency for which that glass is less 'noise absorbent' than for the others. That value is known as critical frequency. See the graphic below:<br />
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<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em;"><tbody>
<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/-NZ25plmC5P0/T-3P3cSXFzI/AAAAAAAAApg/yrZy9mf0kaQ/s1600/1.+thickness+single+glazing.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="566" src="http://3.bp.blogspot.com/-NZ25plmC5P0/T-3P3cSXFzI/AAAAAAAAApg/yrZy9mf0kaQ/s640/1.+thickness+single+glazing.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Sound reduction (in dB) measured at different frequency bands for glass panes of different thickness. Source: Detailing for Acoustics, Lord and Templeton.</td></tr>
</tbody></table>
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A 4 mm-thick glass is rather transparent (poor attenuation measured in dB) for high frequencies at the range of 3500 Hz; 6 mm-thick glass is poor for frequencies around 2000 Hz; and 10 mm-thick glass performs bad at 1300 Hz. The higher the mass the less of a problem critical frequency appears to be: 25 mm-thick glass has no weak point as it can be noted from the graph above.<br />
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An insulating glass unit built with two panes of the same thickness experiences the issue of critical frequency: it is said that the two panes vibrate (resonate) together at that frequency, thus reducing the glass overall acoustic performance.<br />
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For this reason we recommend using different thickness in a double glass unit. A 6-12-4 mm glass will absorb more sound at high frequencies of 2000 Hz (claxon noise) than a 6-12-6 mm glass, in spite of having less mass. On the other hand, at lower frequencies between 125 and 250 Hz (traffic noise) this is not the case: a 6-12-6 mm glass reduces sound more effectively than a 6-12-4 mm glass. At low frequencies sound attenuation is directly proportional to mass.<br />
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<h4>
<b>4/ Laminated vs. monolithic glass</b></h4>
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<div>
A laminated glass will attenuate sound transmission more than a monolithic glass of the same mass. See the graph below:<br />
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<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/--ug7w4G1YAo/T-3QOFbt3pI/AAAAAAAAApo/7lwxsGY27ws/s1600/2.+laminated+vs+solid+single+glazing.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="598" src="http://3.bp.blogspot.com/--ug7w4G1YAo/T-3QOFbt3pI/AAAAAAAAApo/7lwxsGY27ws/s640/2.+laminated+vs+solid+single+glazing.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Sound absortion of monolithic (solid) glass compared to laminated glass with the same mass. Source: Detailing for Acoustics, Lord and Templeton.</td></tr>
</tbody></table>
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A laminated glass of 2+2 mm reduces sound at high frequencies considerably more than a monolithic glass 4 mm-thick (that's 8 to 10 dB of additional attenuation). Why? because the critical frequency effect disappears due to the sound damping provided by polyvinyl butyral (the soft interlayer used to permanently bond the glass panes together dissipates energy by vibration). The same applies to the 3+3 mm laminated against the monolithic 6 mm. In contrast, at low frequencies (traffic noise) the effect of butyral is less pronounced, although it is still positive (about 2 dB increase).<br />
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<h4>
<span class="Apple-style-span" style="font-weight: bold;"><b>5/ Air cavity effect</b></span></h4>
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<div>
Surprise: a standard double glazed unit does not reduce sound transmission much more than a monolithic glass. What matters is the thickness of the air space between glass panes, but only for really wide cavities.<br />
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/-dpP5TfCQ56o/T-3QePAos1I/AAAAAAAAApw/wb5wz3HIBD8/s1600/3.+double+vs+single+glazing.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="624" src="http://2.bp.blogspot.com/-dpP5TfCQ56o/T-3QePAos1I/AAAAAAAAApw/wb5wz3HIBD8/s640/3.+double+vs+single+glazing.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Effect of air space width on the acoustic performance of double glazing. Source: Detailing for Acoustics, Lord and Templeton.</td></tr>
</tbody></table>
The acoustic attenuation of a 6-12-6 mm glass is generally superior to that of a monolithic 6mm-thick glass, but only by 2 or 3 dB, and still there may be low frequency bands where the DGU performs worse. Of course if we compare a 6 mm-monolithic with a double glazed 12-6-10 mm, the sound reduction is much better at the double glazed unit.<br />
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What really matters is the width of the air space, not the small one found at double glazing but the one of a double skin. The ideal cavity width to boost sound attenuation is 200 mm. For widths less than (or greater than) 200 mm the effect is less noticeable (although a wide air space will always perform better than a narrow one). A double glazing with 10 mm air space performs almost like a 20 mm airspace.<br />
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<h4>
<b>6/ Combined air cavity & glass thickness effect</b></h4>
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<div>
The conclusion comes in the last graph: a combination of large thickness, different one between the two panes and wide air space distance (even better if we use laminated glass) provides the maximum noise attenuation. We can reach up to 45dB.<br />
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://4.bp.blogspot.com/-UbaAn8BbORk/T-3QxByydtI/AAAAAAAAAp4/zDae9oOSWr4/s1600/4.+thickness+++cavity+double+glazing.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="640" src="http://4.bp.blogspot.com/-UbaAn8BbORk/T-3QxByydtI/AAAAAAAAAp4/zDae9oOSWr4/s640/4.+thickness+++cavity+double+glazing.png" width="604" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Combined effect of glass thickness and air space on the acoustic performance of double glazing. Source: Detailing for Acoustics, Lord and Templeton.</td></tr>
</tbody></table>
<div>
<br /></div>
<div>
<br /></div>
To achieve this with a conventional double glazing width (about 28-35mm only) we have to employ an acoustic interlayer or a sort of resin between two panes in a laminated glass combined within a DGU. These acoustic interlayers or resins dissipate sound waves much more than two or three PVB interlayers as in a typical laminated glass. Some brands of enhanced acoustical laminated products are:<br />
<ul>
<li>Pilkington <a href="http://www.pilkington.com/products/bp/bybenefit/noisecontrol/optiphon/default.htm" target="_blank">Optiphon</a>.</li>
<li>Saint Gobain <a href="http://uk.saint-gobain-glass.com/b2b/default.asp?nav1=pr&nav2=details&nav3=Comfort&nav4=8078" target="_blank">Stadip Silence</a>.</li>
<li>AGC <a href="http://www.agc-glass.eu/glassday/EN/gg/gg_01_nl.html" target="_blank">Thermobel Phonibel</a>.</li>
<li>Viracon <a href="http://www.viracon.com/index.php?option=com_remository&Itemid=285&func=fileinfo&id=28&lang=en" target="_blank">Saflex SilentGlass</a>.</li>
</ul>
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://4.bp.blogspot.com/-IiQ-mDMdGUQ/T--AyvJ7ClI/AAAAAAAAArc/Y7gEM14akUQ/s1600/Imagen+1.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="328" src="http://4.bp.blogspot.com/-IiQ-mDMdGUQ/T--AyvJ7ClI/AAAAAAAAArc/Y7gEM14akUQ/s640/Imagen+1.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">SGG Stadip Silence effect as part of a double glazed unit. Other brands perform similarly. By the way, the scale below is not frequency but loudness (it measures dB). Taken from Saint Gobain Stadip Silence brochure.</td></tr>
</tbody></table>
<br />
What about the effect of using argon or krypton instead of air? In theory, a higher density gas in the space between panes should have a positive effect on acoustical performance. Comparison testing of standard symmetrical insulating units indicates though that common gases as argon have virtually no increased effect on sound attenuation ratings. While some improvement was noted at some frequencies, resonance effects actually became more pronounced.<br />
<br />
<h4>
7. Some useful values</h4>
<b><i>Rw index:</i></b> The Rw index or sound reduction index (expressed in decibels) measures, in just one number, the acoustic performance of a specific glass unit. The higher the Rw index, the better the level of acoustic insulation offered by that glass composition. The Rw index of ordinary double glazing is around 29 dB whereas a good acoustic interlayer offers an Rw index of around 50 dB.</div>
<br />
Rw is a single figure rating for the airborne sound insulation of building elements (not just glass). It includes a weighting for the human ear and measures actual sound transmittance. Rw is measured in a laboratory, not on site (the site-measured equivalent value has the Egyptian denomination of D<span class="Apple-style-span" style="font-size: x-small;">nT,W</span>). The Rw value is merely an average simplifying mutual comparison of various building components. That can be confusing some times. Two glass units can have the same Rw index while one of them performs well at low frequencies and bad at high ones, and the other one performs just the opposite.<br />
<br />
<b><i>C and C<span class="Apple-style-span" style="font-size: x-small;">tr</span> factors:</i></b> To slightly avoid this issue two spectrum adjustment factors: C and C<span class="Apple-style-span" style="font-size: x-small;">tr</span>, have been added to modulate the Rw average. For sound waves featuring high frequencies, the factor C is added to the Rw value. For lower frequencies, factor C<span class="Apple-style-span" style="font-size: x-small;">tr</span> needs to be added. The acoustic behaviour of a building component is hence defined by three numbers: Rw (C, C<span class="Apple-style-span" style="font-size: x-small;">tr</span>). A building component with the values Rw (C, C<span class="Apple-style-span" style="font-size: x-small;">tr</span>) = 40 (-1, -4) provides an average insulation performance of 40 dB. For higher pitched sounds the sound insulation is lessened by 1 dB (39 dB) and for lower pitched sound sources it is lessened by 4 dB (36 dB).<br />
<br />
The table below, extracted from Saint Gobain, helps showing how these three numbers apply to different laminated units with acoustic interlayers:<br />
<br />
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/-Ja-ld71zFlE/T_CHvqEZXsI/AAAAAAAAAro/9rS0FBMQrZk/s1600/Imagen+1.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="296" src="http://3.bp.blogspot.com/-Ja-ld71zFlE/T_CHvqEZXsI/AAAAAAAAAro/9rS0FBMQrZk/s640/Imagen+1.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Sound reduction index values for several laminated glass units with acoustic interlayers. The thickness shown at the right column is the total one. 13 mm means 6 mm + 6 mm + 0.8 mm interlayer. Taken from Saint Gobain Stadip Silence brochure.</td></tr>
</tbody></table>
<div>
<br /></div>
<div>
C takes into account medium and high frequency noise sources such as TV, music, loud conversations or aircraft noise a short distance away. C<span class="Apple-style-span" style="font-size: x-small;">tr</span> takes into account medium and low frequency noise sources such as urban traffic noise or aircraft noise a long distance away.<br />
<br />
<b><i>Pink Noise:</i></b> Expressed in dB(A), this is an assessment of the sound insulating properties of a building material over specified standard frequencies, which represent general activity noise when <i>equal levels of power are applied at each frequency</i>. So, in pink noise each octave carries an equal amount of noise power. Funnily: the name arises from the pink appearance of visible light with this power spectrum.<br />
<span class="Apple-style-span" style="font-family: sans-serif; font-size: 14px; line-height: 21px;"><br /></span></div>
<div>
<b><i>Ra: </i></b>Ra is the abbreviation for the sound reduction index when the spectrum adaptation term C is applied to the single number weighted sound reduction index (Rw), <i>using pink noise</i> as a sound source.<br />
<div>
<br /></div>
<div>
<div>
<b><i>Ra,tr:</i></b> Ra,tr is the abbreviation for the sound reduction index when the spectrum adaptation term C<span class="Apple-style-span" style="font-size: x-small;">tr</span> is applied to the single number weighted sound reduction index (Rw) <i>using pink noise</i> as a sound source.<b><i><br /></i></b></div>
<div>
<div>
<br />
<div>
<div>
<div>
So far so good. Acoustic performance of glass should now be less of a dark matter for us. But this is not all: remember that detailing to achieve a proper air tightness between glass and frame will always be required! Loose gaskets can severely harm the best glass selection for acoustics...<br />
<br /></div>
</div>
</div>
</div>
</div>
</div>
</div>Ignacio Fernández Sollahttp://www.blogger.com/profile/03918193520738485621noreply@blogger.com131tag:blogger.com,1999:blog-1298203288964657974.post-47379797243766806812012-05-28T01:13:00.005+02:002012-06-11T00:58:02.458+02:00Sydney Opera House: decoding the glass walls<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/-1vOllUfmU3M/T8Cx3RR_CSI/AAAAAAAAAf0/nEoBL4HBeKc/s1600/Red+Book+sketch+1958.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="240" src="http://2.bp.blogspot.com/-1vOllUfmU3M/T8Cx3RR_CSI/AAAAAAAAAf0/nEoBL4HBeKc/s640/Red+Book+sketch+1958.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Utzon's sketch of the Sydney Opera House. The Red Book, 1958.</td></tr>
</tbody></table>
First, a confession: I've never been to Australia. Is it possible to 'decode' a complex element of the <a href="http://www.sydneyoperahouse.com/the_building.aspx" target="_blank">Sydney Opera House</a> as the external glass walls without having ever visited the building? The obvious answer is no, but one doesn't lose much with trying.<br />
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<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/-325_01ZiNTI/T8Ju3aAlJaI/AAAAAAAAAkE/9N1wiCpnUtY/s1600/Jorn+Utzon.jpg" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="400" src="http://3.bp.blogspot.com/-325_01ZiNTI/T8Ju3aAlJaI/AAAAAAAAAkE/9N1wiCpnUtY/s400/Jorn+Utzon.jpg" width="300" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Jorn Utzon</td></tr>
</tbody></table>
Then, there is some consolation in the fact that Jorn Utzon himself never saw the glass walls as they are now - he didn't even take part in their final design. This is the second most important feature of the facade of the Sydney Opera House - after the concrete shells of course - and it is not an Utzon design at all: Utzon left the site in 1966 and the glass walls were designed and built bewteen 1970 and 1972. <br />
<br />
In this post we will not deal with the concrete shells or the precast enamelled porcelain cladding of the shells. Our focus are the glazed walls located at both ends and long sides of the three main buildings above the podium: the Concert Hall, the Opera Theatre and the Restaurant.<br />
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<div class="separator" style="clear: both; text-align: center;">
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<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/-xey2K7Ob3ic/T71ap__R-pI/AAAAAAAAAfc/6RvqDTumyLM/s1600/SOH,+A4+wall+during+glazing.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="386" src="http://2.bp.blogspot.com/-xey2K7Ob3ic/T71ap__R-pI/AAAAAAAAAfc/6RvqDTumyLM/s640/SOH,+A4+wall+during+glazing.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Glazing of the Concert Hall north end, 1972.</td></tr>
</tbody></table>
<br />
Many questions arose when I started digging: are the glazed walls at least partly Utzonian? Who were their designers? Was it a smooth process - since the Danish architect was not there any longer - or was it another nightmare within the general conundrum of the job? And finally, is there anything we can learn from the Sydney Opera House glass walls, now that we celebrate 40 years after their conclusion?<br />
<br />
<b>The glass walls during the competition and first stages of design.</b><br />
Let's start at the beginning. It is November 1956 in Hellebaek, Denmark. Jorn Utzon, a young architect (38 at the time) has spent all his spare time during the last six months working at the design of an Opera House for a competition in Sydney, Australia. He has of course not visited the site - it would be too strenous and expensive an effort. His main ideas for the design are already defined: the unifying podium, the decision of splitting the opera hall and the theatre in two parallel buildings plus a smaller one housing a restaurant, a number of concrete shells flying above the three volumes.<br />
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<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/-ig7JPxnfq2o/T8IPOD7xV4I/AAAAAAAAAhk/aCWM-3hfGgs/s1600/Competition+section,+1956.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="270" src="http://3.bp.blogspot.com/-ig7JPxnfq2o/T8IPOD7xV4I/AAAAAAAAAhk/aCWM-3hfGgs/s640/Competition+section,+1956.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Competition section drawn by Utzon, 1956.</td></tr>
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<br />
<br />
Natural light is not a critical requirement for an opera house; concerts and theatre plays happen mostly at night. But views of the Sydney bay are magnificent at the point where the buildings will be located, and Utzon's design gives predominance to the two short ends of the main buildings: one edge overlooking the bay, the other receiving visitors from the city. What did Utzon imagine for those large gable ends behind the shells? Around the end of the <a href="http://gallery.records.nsw.gov.au/index.php/galleries/sydney-opera-house/sydney-opera-house-drawings/" target="_blank">competition</a> (see above) he quickly draw a longitudinal section showing vertical glass walls hanging from the outer shells and suddenly twisting out to become almost horizontal glazed canopies. At one side (north, overlooking the bay) the glazed canopies cover the space of the back foyers. At the other side (south, looking to the city) they are part of the entrance space receiving the visitors.<br />
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/-UqLXjutMulE/T8DBLaMmm2I/AAAAAAAAAgQ/7PZ1j2L_mUk/s1600/SOH+Plan+1957.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="472" src="http://3.bp.blogspot.com/-UqLXjutMulE/T8DBLaMmm2I/AAAAAAAAAgQ/7PZ1j2L_mUk/s640/SOH+Plan+1957.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">SOH - Plan, 1957. North is at the left side. Top: Theatre. Down: Opera and restaurant.</td></tr>
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<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/-2gzxiDqzDg8/T8DA4-PQwaI/AAAAAAAAAgI/xBtGFUYjnqM/s1600/SOH+model+1957.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="430" src="http://1.bp.blogspot.com/-2gzxiDqzDg8/T8DA4-PQwaI/AAAAAAAAAgI/xBtGFUYjnqM/s640/SOH+model+1957.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">SOH - South view, first model 1957. From left to right: restaurant, Opera and Theatre buildings.</td></tr>
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<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/-NFwhFLxalOk/T8IKDn4AzQI/AAAAAAAAAhI/ggpyzlJ0G0c/s1600/Imagen+2.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="474" src="http://3.bp.blogspot.com/-NFwhFLxalOk/T8IKDn4AzQI/AAAAAAAAAhI/ggpyzlJ0G0c/s640/Imagen+2.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">SOH - North view, first model 1957. Left: Theatre; right: Opera Hall building.</td></tr>
</tbody></table>
Jump to late spring 1957. The competition had been awarded on January that year and Utzon had come up as the winner. He is rushing with the preparation of additional drawings and a model (the first one) to take with him for his first visit to Sydney. The north shells are now taller, and the south ones shorter.<br />
<br />
The model (see the two images above, south and north sides) has a first visualization of the glass walls. They look like a simplified version of the competition scheme: there are no horizontal glazed canopies, and the upper part of the glass walls is covered with what looks as horizontal louvres. Remember we are in Australia; midday sun shines at the north side and louvres here appear on both sides. This proposal was not going to last.<br />
<br />
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://4.bp.blogspot.com/-aKpEr6vzSlk/T8IKtZq2dXI/AAAAAAAAAhQ/LQl123CUZx4/s1600/Imagen+4.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="432" src="http://4.bp.blogspot.com/-aKpEr6vzSlk/T8IKtZq2dXI/AAAAAAAAAhQ/LQl123CUZx4/s640/Imagen+4.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Cover of the Red Book, prepared by Utzon in 1958.</td></tr>
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<br />
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/-ZiBZiuFoShA/T8DIBXfqSsI/AAAAAAAAAgc/rsxWCiKzbKg/s1600/Imagen+2.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="640" src="http://1.bp.blogspot.com/-ZiBZiuFoShA/T8DIBXfqSsI/AAAAAAAAAgc/rsxWCiKzbKg/s640/Imagen+2.png" width="489" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Platform level with zig-zag vertical glass walls, 1958.</td></tr>
</tbody></table>
Further jump, now to spring 1958. Utzon has just completed a preliminary summary of the project at his office in Hellebaek, before returning to Sydney to meet with his client for the second time. The design and a supporting text are encased in an elegant publication with a vermillion cover: it would become known as <a href="http://gallery.records.nsw.gov.au/index.php/galleries/sydney-opera-house/sydney-opera-house-the-red-book/" target="_blank">the Red Book</a>.<br />
<br />
The design for the glass end walls adopts a different configuration: they are now zig-zagging in plan and vertical in section, looking like a folding screen (see plan above and section below). This makes sense from a structural point of view because the different folded planes stiffen one another against wind loads. A second look at the longitudinal section below explains why these glazed elements are so stiff: the roof shells in the Red Book are still rather low, thus requiring an edge support at the glass walls. So these woud have to incorporate some kind of steel mullions transmitting the roof loads down to the podium.<br />
<br />
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/-PefI8N0i05w/T8H3TeGy52I/AAAAAAAAAgo/Oa4ecUX5fGQ/s1600/Imagen+6.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="262" src="http://3.bp.blogspot.com/-PefI8N0i05w/T8H3TeGy52I/AAAAAAAAAgo/Oa4ecUX5fGQ/s640/Imagen+6.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Longitudinal section of the Concert Hall, Red Book 1958. Notice the folding screen glass ends.</td></tr>
</tbody></table>
The elevations show the glass walls divided in rectangular pieces with discontinued horizontal transoms. The longitudinal section deals (rather unsucessfully) with one of the future problems of the glazed walls: how they connect with the curved inner side of the shells. A vertical, folding screen plan as proposed here would obviously make this connection a nightmare.<br />
<br />
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://4.bp.blogspot.com/-zQ5tMjJsEXM/T8H5nzLVwxI/AAAAAAAAAgw/jmw60j5FVRo/s1600/Imagen+4.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="358" src="http://4.bp.blogspot.com/-zQ5tMjJsEXM/T8H5nzLVwxI/AAAAAAAAAgw/jmw60j5FVRo/s640/Imagen+4.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">West elevation of the Concert Hall, Red Book 1958. Transoms are located at different heights; the folding screen at left masks roof-supporting columns for the north shell.</td></tr>
</tbody></table>
<br />
<br />
The proposal for the glass walls shown at the Red Book (the third version of this element) would have no continuation, as the previous two. It is clear that Utzon, in the period between 1956 and 1962, was more interested in developing first the general concept, then the podium and finally the shell roofs of the Opera House. The glass walls, as many other important design elements, had to wait. This design process so dear to Utzon - progressing element by element - would prove to be a crucial mistake and was part of the crisis that would eventually force his resignation from the project in 1966.<br />
<br />
<b>The glass walls in Utzon's project for Stage II</b><br />
It soon became clear that the whole Opera House process would take a long time to design and build. The client, the architect and the engineers agreed in splitting the design and construction process in three stages: Stage I for Podium; Stage II for the roof shells and Stage III for glass walls plus interiors.<br />
<br />
The construction of the Sydney Opera House started by the podium in March 1959, based on the Red Book designs with some modifications, finally approved in April 1958. As the construction of the podium progressed, Utzon and the engineers of Ove Arup and Partners continued to progress on the roof shells design, both in Hellebaek and London. The geometry of the shells presented in the 1958 Red Book was based on a parabola. Since this presented several engineering and construction problems a long period of proposals ensued, until in the autumn of 1961 Utzon came up with the proposal of using a sphere as the geometry for the surface of the shells. This was supported by Ove Arup and allowed the engineers to finally produce calculations and construction drawings for the shells in 1962 - 63.<br />
<br />
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/-I7E6DhI8oNQ/T8IHXj8iW7I/AAAAAAAAAg8/aOv4VtmA810/s1600/Cover+of+the+Yellow+Book.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="424" src="http://3.bp.blogspot.com/-I7E6DhI8oNQ/T8IHXj8iW7I/AAAAAAAAAg8/aOv4VtmA810/s640/Cover+of+the+Yellow+Book.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Cover of Utzon's Yellow Book, dated 1962.</td></tr>
</tbody></table>
In the spring of 1962 Utzon returned to Sydney in order to present the Stage II architectural diagrams along with Jack Zunz, head of the engineering team in Ove Arup and Partners. Utzon's presentation - the next one after the Red Book - would be called <a href="http://gallery.records.nsw.gov.au/index.php/galleries/sydney-opera-house/sydney-opera-house-the-yellow-book/" target="_blank">the Yellow Book</a> because of the colour of its cover.<br />
<br />
In the Yellow Book, unlike for years ago with the Red Book, Utzon and his team present for the first time a well-thought proposal for the glass walls, at least in geometrical terms. Now the edge shells, based in a spherical shape, are higher and more pointed than the first shells. The now self-standing superstructure no longer required the complementary support considered in the Red Book four years earlier. The glazed facades could become the light membranes first envisaged during the competition: curtain walls, suspended under ogival arches, formed by blades of glass mounted in slim frames. In a letter from 1965 Utzon explained (as quoted by <a href="http://books.google.es/books/about/J%C3%B8rn_Utzon.html?id=mTNUAAAAMAAJ&redir_esc=y" target="_blank">Françoise Fromonot in '<i>Jorn Utzon. The Sydney Opera House</i>'</a>):<br />
<blockquote class="tr_bq">
"The problem that faced me was to create a glazing system sufficiently flexible to make up the irregular overall shape and have sufficient strength to resist the wind loads imposed over such a vast area".</blockquote>
And he continued:<br />
<blockquote class="tr_bq">
"Our early attempts to use composite structures of concrete and steel or bronze were too complicated and too rigid. The answer was to be found in a simple geometrical system consisting of a series of glass panels of modular size held between flexible mullions which can be adjusted to any shape and portion as required". </blockquote>
Utzon selected tubular plywood as the preferred material for these mullions, and he abandoned the sheer verticality of his previous solutions to embrace articulated membranes, "like the wings of a bird".<br />
<br />
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/-SCEo4yR_jR4/T8IRoW8wDPI/AAAAAAAAAhs/hNZ_9XHaHKs/s1600/Glass+wall+principle+from+the+1962+Yellow+Book.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="480" src="http://1.bp.blogspot.com/-SCEo4yR_jR4/T8IRoW8wDPI/AAAAAAAAAhs/hNZ_9XHaHKs/s640/Glass+wall+principle+from+the+1962+Yellow+Book.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Glass wall principle from the 1962 Yellow Book.</td></tr>
</tbody></table>
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://4.bp.blogspot.com/-S7lYtjQeO9k/T8IR2JD5xoI/AAAAAAAAAh4/ZfyD7d8wZ30/s1600/Seabird+wings.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="316" src="http://4.bp.blogspot.com/-S7lYtjQeO9k/T8IR2JD5xoI/AAAAAAAAAh4/ZfyD7d8wZ30/s640/Seabird+wings.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Reference image for the new mullions idea: sea bird, picture by Emil Schultess.</td></tr>
</tbody></table>
Utzon illustrated this metaphor with an image of a seagull in flight. The glass walls now curved out in overlapping sections from top to bottom, from vertical at the summits of the vaults to near horizontal above the platform. At the lower end, their tales formed transparent canopies over the glass doors that provided access to the foyers. The folding mullions implied the absence of a dead-loading mission as well as eliminating reflections in the glass.<br />
<br />
The images below are taken from the Yellow Book and show the application of the plywood mullions to the north and south glass walls.<br />
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<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/-PuIqNZY5ybE/T8ILmTi1G9I/AAAAAAAAAhY/hZ64svjv9tU/s1600/Northern+glass+wall+1.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="364" src="http://2.bp.blogspot.com/-PuIqNZY5ybE/T8ILmTi1G9I/AAAAAAAAAhY/hZ64svjv9tU/s640/Northern+glass+wall+1.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Side elevation and plan of the northern glass wall framing. Yellow Book, 1962.</td></tr>
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<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/-ttmLfblVWIk/T8IWdfC1HqI/AAAAAAAAAiE/9D8Gk052l6U/s1600/Section+and+elevation+northern+glass+wall.+Yellow+Book+1962.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="384" src="http://1.bp.blogspot.com/-ttmLfblVWIk/T8IWdfC1HqI/AAAAAAAAAiE/9D8Gk052l6U/s640/Section+and+elevation+northern+glass+wall.+Yellow+Book+1962.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Section and front elevation of the northern glass walls. Yellow Book, 1962.</td></tr>
</tbody></table>
<br />
<br />
<b>Development of the glass walls by Utzon during Stage III</b><br />
In March 1963, a year after the presentation of the Yellow Book, Utzon moved to Australia to live there with his family. Construction of the Opera House roofs was well underway and he was occupied - finally - developing his proposals for the glass walls and the interiors.<br />
<br />
For both elements Utzon had decided to use innovative plywood technology. It may seem a little incongruous to develop timber profiles as structural elements for immense glass walls, but it followed a joint research undertaken by the architect with the Australian company Ralph Symonds Ltd, experts in reconstituted wood for industrial use. Ralph Symonds, a short man but a visionary industrialist, set up a vacuum bagging process and very large presses so that plywood could be made in 50 foot long sheets (about 18 metres), which was at the time an enormous length of plywood. Utzon saw this and realised that by using Symonds' vacuum bagging process he could achieve large sections in plywood spanning long distances. These sections were going to be the lining systems of the small theatres underneath the podium of the Opera House and the corridors. And they were the right material for the mullions at the glass walls as well.<br />
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<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/-Scx9aHPcEfU/T8I4vyKfV2I/AAAAAAAAAiQ/8ypodsqvzqQ/s1600/plywood+mullions+as+standard+elements.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="306" src="http://2.bp.blogspot.com/-Scx9aHPcEfU/T8I4vyKfV2I/AAAAAAAAAiQ/8ypodsqvzqQ/s640/plywood+mullions+as+standard+elements.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Plywood mullions as standard elements - Architect's models, end of 1964.</td></tr>
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The mullions were to be built up bonding seven layers of 13mm white Soraya pine plywood sheet into 600mm deep x 90m wide sections. The layers could be stepped to accomodate all mullion configurations. On either side of the timber mullion the external layer would be curved to form a U-shaped channel to which the glass would be fixed by a normal screwed-on clip system. Finally a U-formed cover piece would enclose the outer mullion front. To resist external weather conditions these cover pieces were going to be finished in hot-bonded bronze sheets.<br />
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The mullions were to be prefabricated and then assembled on site, like a Meccano set. The result, to Utzon satisfaction, combined the design of pieces suited to their role with the accuracy of industrial craftmanship.<br />
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<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/-KwK94_T_Z8E/T8I-ddlDKaI/AAAAAAAAAi4/TEWwWqB4ZOM/s1600/Imagen+9.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="272" src="http://3.bp.blogspot.com/-KwK94_T_Z8E/T8I-ddlDKaI/AAAAAAAAAi4/TEWwWqB4ZOM/s640/Imagen+9.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Plan section and model from 1964 showing the standardisation solution for the south walls.</td></tr>
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<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/-neGJx89salo/T8I9zn6mYpI/AAAAAAAAAiw/gpkHnOKg-xg/s1600/Imagen+5.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="550" src="http://1.bp.blogspot.com/-neGJx89salo/T8I9zn6mYpI/AAAAAAAAAiw/gpkHnOKg-xg/s640/Imagen+5.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Model dated end of 1964. Concourse view with plywood mullions, south side.</td></tr>
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<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/-TuOQ617fwdI/T8I9C4KAqTI/AAAAAAAAAio/rGEnWwvxTU8/s1600/Imagen+4.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="400" src="http://2.bp.blogspot.com/-TuOQ617fwdI/T8I9C4KAqTI/AAAAAAAAAio/rGEnWwvxTU8/s400/Imagen+4.png" width="366" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">View from the harbour (north), model 1964.</td></tr>
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The drawings prepared by the architect's team on site between 1964 and 1965 show all glass walls in the same grid of 1.2m wide, reflecting the dimension of the paving slabs of the platform, visually conveying this dimension up to the peaks of the vaults. In the last drawings from 1966 the glass width has been reduced to 91cm (3 feet). Glass would be laminated for safety reasons, the panels being specified in commercially available dimensions.<br />
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On the last model produced under Utzon's supervision - dated early 1966 - the glass walls have a more vigorous quality; transoms have been totally suppressed and the mullions fall directly onto the bottom platform. The mullions are thin and deep: viewed from the side the facades would be perceived as an opaque layering (see the two images below).<br />
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<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/-xnTZsTt_aYU/T8I82h5_VuI/AAAAAAAAAig/lFfP-XHgXI4/s1600/Imagen+6.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="614" src="http://2.bp.blogspot.com/-xnTZsTt_aYU/T8I82h5_VuI/AAAAAAAAAig/lFfP-XHgXI4/s640/Imagen+6.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Model from early 1966, section of the Major Hall outlooking the bay. Mullions here come down to the foyer floor.</td></tr>
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<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://4.bp.blogspot.com/-XGRIyKalNPk/T8I_ZC7tygI/AAAAAAAAAjI/oUXqKcs1FGA/s1600/Imagen+8.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="560" src="http://4.bp.blogspot.com/-XGRIyKalNPk/T8I_ZC7tygI/AAAAAAAAAjI/oUXqKcs1FGA/s640/Imagen+8.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Model from early 1966, North view from the harbour. </td></tr>
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<tr><td style="text-align: center;"><a href="http://4.bp.blogspot.com/-arqhH2qw2TU/T8JQBRBatNI/AAAAAAAAAjU/aroKO1tpzpM/s1600/Imagen+2.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="496" src="http://4.bp.blogspot.com/-arqhH2qw2TU/T8JQBRBatNI/AAAAAAAAAjU/aroKO1tpzpM/s640/Imagen+2.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">A recent view of the last section model prepared under Utzon's supervision in 1966.</td></tr>
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Was the last of Utzon's ideas for the glass walls feasible from a technical point of view? Jack Zunz, the engineer from Arups on site, always said no. If we apply the knowledge of our day to this plywood mullion concept the probable answer is once again negative. Because of a number of reasons: spans were huge, there was no lateral stifness, geometry was not solved yet (glass would have to assume a tri-dimensional surface), and it is doubtful that bonded plywood from the sixties would have resisted for a long term in a maritime environment.<br />
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In any case the question above is irrelevant. The new Australian government was willing to get rid of Utzon and minister for Public Works David Hughes refused to approve the plywood mock-ups for the auditoria ceilings. This, among other issues, forced Utzon to present a letter temporarily withdrawing as the Opera House architect on 28 February 1966, resignation that was immediately accepted. A new period was about to start for the glass walls design, now and forever beyond Utzon's command.<br />
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<b>Final design Stage III - rethinking the glass walls</b><br />
On April 1966, minister Hughes announced the three new architects appointed to complete the Opera House: Peter Hall, 34, design architect; Lionel Todd, 36, supervision; and David Littlemore, 55, documents. Ove Arup and Partners would remain as project and site engineers.<br />
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Stage I of the works, including the steps, concourse and platforms had finished in January 1963. Nine months after Hall, Todd and Littlemore had taken charge, in January 1967 the last tile lid was lowered into position and the roof shells - including their cladding - were complete, ending the Stage II of the works.<br />
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When they took over the design development of Stage III, Hall, Todd and Littlemore were to be busy with two questions : the seating capacity of the Opera Hall (later downgraded into a Concert Hall due to lack of space) and acoustics. More than two years after the new architects had taken charge the government approved the new programme, and site work on Stage III commenced in 1969.<br />
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<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/-nH_xuK-HB-c/T8JRF6EtknI/AAAAAAAAAjc/WRgIuz6KwWU/s1600/Imagen+2.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="640" src="http://2.bp.blogspot.com/-nH_xuK-HB-c/T8JRF6EtknI/AAAAAAAAAjc/WRgIuz6KwWU/s640/Imagen+2.png" width="612" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Code names for the different glass walls designed between 1967 and 1970. Image taken from Harry Sowden, 'Sydney Opera House glass walls', published in 1972.</td></tr>
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The concept of the scheme finally selected for the glass walls by Peter Hall with assistance of the Arups team, a continuous glass surface enclosing a steel structure, dates from mid-1967. This concept was developed for more than two years and involved much research into a wide range of façade materials and techniques.<br />
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It is quite easy to undervalue the work taken by Peter Hall and the team of architects and engineers that were to finish the Opera House after Utzon's dismissal. I find that a very unfair position, at least for the glass walls part. As David Croft, Arups design engineer dealing with the glass walls development would say at the time:<br />
<blockquote class="tr_bq">
"The glass walls are an epitome of the problems of the whole of the Opera House (...). Every day I find it more complicated than it was before. The more you do the more there is to do"</blockquote>
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<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/-9L8VaEDcpuQ/T8JjZlH6MpI/AAAAAAAAAjo/ouhwsjv-hdI/s1600/Michael+Lewis+and+David+Croft.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="334" src="http://3.bp.blogspot.com/-9L8VaEDcpuQ/T8JjZlH6MpI/AAAAAAAAAjo/ouhwsjv-hdI/s640/Michael+Lewis+and+David+Croft.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Michael Lewis' hands drawing the glass walls in the air, and David Croft at his office on site. </td></tr>
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The last part of this post will demonstrate up to what point the final glass walls solution owes to the previous concepts designed by Utzon and where it departs from those to make the whole thing possible. I have based my information on two sources, not easy to find today, both bearing the same name: 'The Sydney Opera House glass walls'. The first is <a href="http://es.scribd.com/doc/95260056/Arup-Journal-1973-Sydney-Opera-House-glass-walls" target="_blank">a paper written by David Croft and John Hooper</a>, engineers from Arup, published at <i>The Arup Journal</i> in October 1973. The second is <a href="http://es.scribd.com/doc/94594923/Sydney-Opera-House-Glass-Walls-Harry-Sowden" target="_blank">a book written by photographer Harry Sowden</a> with contributions from Peter Hall, David Croft, John Hooper, Bob Kelman and Michael Lewis, all engineers from Ove Arup and Partners on site, and self-published in 1972. Most of the black and white images shown from here below come from this book.<br />
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<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://4.bp.blogspot.com/-GWXBXyvNuqg/T8KVX3tApZI/AAAAAAAAAk4/0yAlhOUKZyg/s1600/Imagen+3.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="290" src="http://4.bp.blogspot.com/-GWXBXyvNuqg/T8KVX3tApZI/AAAAAAAAAk4/0yAlhOUKZyg/s640/Imagen+3.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">The three buildings as built, looking south: Restaurant (left), Concert Hall and Theatre Hall. </td></tr>
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<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://4.bp.blogspot.com/-CIhGgndOWTU/T8KWYoO1S0I/AAAAAAAAAlA/BIY0u5DbskQ/s1600/Southern+glass+wall+1.jpg" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="424" src="http://4.bp.blogspot.com/-CIhGgndOWTU/T8KWYoO1S0I/AAAAAAAAAlA/BIY0u5DbskQ/s640/Southern+glass+wall+1.jpg" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Theatre Hall: southern glass wall seen from bottom up.</td></tr>
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<b>Providing the final concept</b><br />
Despite much technical discussion, investigation and studies, no detailed technical solutions were available for the glass walls at the time of Utzon's dismissal from the project in February 1966. But at least the architect's requirements could be clearly identified as follows:<br />
<ol>
<li>All the glass walls throughout the Opera House are to be read as one family, with a similar structural layout.</li>
<li>The structure shall be as clean as possible, with bracing kept to a minimum if not eliminated.</li>
<li>The mullions shall not be read as supporting the shells: the glass walls shall look as hanging from the shells instead.</li>
<li>Mullions shall be as thin, continuous fins throughout the glass walls.</li>
<li>Below the roofs there shall be as little visual obstruction as possible.</li>
<li>The mullion frames shall be constructed as a series of constant-section units, marking by their position a continuously varying shape across the width of the glass walls.</li>
</ol>
<div>
Peter Hall from Hall, Todd and Littlemore begun working in the glass walls at the beginning of 1967. The material favoured by Hall for the mullions (probably with some positive comments from the Arup engineering team) was steel instead of plywood. But this still required a different material or protection for the outer side of the mullions, exposed to maritime conditions. Concrete was investigated but with unacceptable aesthetic results. The time had come to review the whole philosophy of the glass walls. This was done via a workshop at the London office of Ove Arup & Partners. Peter Hall was there from the architects, and Jack Junz, Michael Lewis and Yuzo Mikami from Arups, with some participation from Ove Arup himself.</div>
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<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/-5gybtLQzzW8/T8JtoMkG1VI/AAAAAAAAAj8/Tfg1r2GmnyQ/s1600/Lewis,+Arup+and+Zunz.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="502" src="http://2.bp.blogspot.com/-5gybtLQzzW8/T8JtoMkG1VI/AAAAAAAAAj8/Tfg1r2GmnyQ/s640/Lewis,+Arup+and+Zunz.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">From left to right: Michael Lewis, Ove Arup and Jack Zunz on site during Stage II construction.</td></tr>
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<div>
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<div>
Point 3 above presented a key isue to solve: because of the differing geometry of the roof and podium structures the mullions had to be bent outwards in vertical section, thus achieving a usable plan area at the bottom, greater than that covered by the shells. And to make the mullions look like hanging from the shells it was necessary that they were effectively fixed at their top edge and then fall in vertical down to a certain point. This lead to a geometry for the two most complex walls, those overlooking the harbour at the Concert and Theatre Halls (A4 and B4 respectively, see above plan with name indications), that would be the combination of a cylinder and two cones, all with their axis located in one same vertical line. See the image and picture below for clarity. </div>
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<tr><td style="text-align: center;"><a href="http://4.bp.blogspot.com/-qWvxUpemYsg/T8JrwGdMc_I/AAAAAAAAAj0/T3cHl_WkMTk/s1600/The+geometry+of+glass+walls+A4+&+B4.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="640" src="http://4.bp.blogspot.com/-qWvxUpemYsg/T8JrwGdMc_I/AAAAAAAAAj0/T3cHl_WkMTk/s640/The+geometry+of+glass+walls+A4+&+B4.png" width="636" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">The final geometry of glass walls A4 and B4 (those overlooking the bay at north elevation)</td></tr>
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<div>
The top part of the glass wall belongs to a cylinder, it then intersects with an inclined cone, and this one intersects again with a lower cone, resulting in an opening-out section as it moves down.</div>
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<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/-G_VlcUZjCYI/T8KXN4ZsUJI/AAAAAAAAAlI/yKOX9Xb9ApU/s1600/Northern+glass+wall+general.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="450" src="http://1.bp.blogspot.com/-G_VlcUZjCYI/T8KXN4ZsUJI/AAAAAAAAAlI/yKOX9Xb9ApU/s640/Northern+glass+wall+general.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Northern glass walls as built: B4 to the left (Theatre) and A4 to the right (Concert Hall).</td></tr>
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<div>
New principles incorporating some of the ideals expressed by Utzon were developed and refined. The choice of material, method of fixing and sealing, all required solutions which had to be worked out from first principles. The task of fitting a suitable glass wall shape into an already completed structure without any plane surfaces demanded much study and effort. Many proposals were tried and rejected throughout the design period, which lasted from September 1967 to May 1971. But in the end the glass walls were eventually built.<br />
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<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/-9Sy0__hg9T4/T8KSnMYnq1I/AAAAAAAAAkg/qGOeFPsb5eQ/s1600/Imagen+2.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="318" src="http://1.bp.blogspot.com/-9Sy0__hg9T4/T8KSnMYnq1I/AAAAAAAAAkg/qGOeFPsb5eQ/s640/Imagen+2.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Glass wall A4 (north Concert Hall). Elevation with and without glass.</td></tr>
</tbody></table>
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<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/-ilNTIBHyKzY/T8KS_fjUklI/AAAAAAAAAko/U4X0YGSK944/s1600/Imagen+4.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="296" src="http://2.bp.blogspot.com/-ilNTIBHyKzY/T8KS_fjUklI/AAAAAAAAAko/U4X0YGSK944/s640/Imagen+4.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Glass wall A4. Plan with and without glass. Notice the horizontal bracing at the central axis.</td></tr>
</tbody></table>
<b>Glass walls A4 and B4</b><br />
With an agreed concept, the detailed desig of the glass walls was carried out in parallel with their construction. Design work was initially concentrated on wall A4, bearing in mind that the details as they evolved would also have to apply to the other walls.<br />
<br />
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://4.bp.blogspot.com/-BTGq6eV2bcc/T8KTbgcxIAI/AAAAAAAAAkw/LN0OGihq-sk/s1600/Imagen+5.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="400" src="http://4.bp.blogspot.com/-BTGq6eV2bcc/T8KTbgcxIAI/AAAAAAAAAkw/LN0OGihq-sk/s400/Imagen+5.png" width="348" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Glass wall A4. Side elevation</td></tr>
</tbody></table>
The choice of glass was a chapter in itself. The main requirement was for a safety glass that could be cut to shape on site. Toughened glass was thus rejected and laminated glass was chosen. At that time these was little information available to the use of laminated glass in buildings, so a research and testing programme was put in place. The laminate finally selected consists on a 12mm layer of clear plate or float glass and a 6mm layer of bronze tinted glass, bonded together with a 0.76mm double interlayer of clear polyvinyl butyral. The intention was to avoid the image of 'green glass' that would have come out if 18mm clear laminated had been selected, plus the advantage of solar shading provided by tinted glass in the highly exposed north orientations.<br />
<br />
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/-EQSBNZctn30/T8KRj_E_sKI/AAAAAAAAAkY/ezugk4VIciw/s1600/Pot-cast+and+float+glass.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="300" src="http://3.bp.blogspot.com/-EQSBNZctn30/T8KRj_E_sKI/AAAAAAAAAkY/ezugk4VIciw/s640/Pot-cast+and+float+glass.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Pot-cast glass (left) and float glass (right): manufacturing the two lites of the laminated piece.</td></tr>
</tbody></table>
<br />
The precise tint (called demi-topaze) was created by a glass supplier in France and applied through a process named pot-casting, then the 6mm tinted lite was laminated to a 12mm clear lite in a different factory near Paris and finally the laminated was pre-cut and shipped to Sydney. The maximum sheet size required on site was approximately 4.0m by 2.1m.<br />
<br />
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/-m0_-WlTj2vk/T8sr9PPsixI/AAAAAAAAApI/rKDBoCEixqU/s1600/Glass+sheets+shapes+and+dimensions.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="288" src="http://3.bp.blogspot.com/-m0_-WlTj2vk/T8sr9PPsixI/AAAAAAAAApI/rKDBoCEixqU/s640/Glass+sheets+shapes+and+dimensions.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Glass sheets size (left, wall A4) and example of a cutting list made in 1970</td></tr>
</tbody></table>
<br />
<b>Glass support system</b><br />
In the main surfaces each glass sheet is supported along its two 'vertical' sides by glazing bars, and the top and bottom horizontal joints are filled with silicone rubber sealant. The glazing bars were extruded from manganese bronze and in their standard form consist of a T-section and a cover piece screwed on after the final positioning of the glass. The combined sections act together as an I-section. The glazing bars follow the lines of the structural mullions inside and each glass sheet is held vertically by two steel pins projecting from the flage of the T-piece.<br />
<br />
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/-yiwJqCYkNk0/T8KQVfHWdlI/AAAAAAAAAkQ/rtOQl3G6YM8/s1600/Glass+fixing+bracket.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="430" src="http://2.bp.blogspot.com/-yiwJqCYkNk0/T8KQVfHWdlI/AAAAAAAAAkQ/rtOQl3G6YM8/s640/Glass+fixing+bracket.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Glass fixing bracket conecting the T-shape (upper right) to the steel mullion (bottom right)</td></tr>
</tbody></table>
<br />
The glazing bars are attached to the structure by means of fixing brackets at roughly 0.9m centres. These brackets had to be adjustable to accomodate the geometrical variations in angle and distance between structural mullion and glass. The fixing proved to be quite a complex piece of machinery and advice was sought from the aircraft industry. The design was developed in conjunction with Hawker de Havilland Pty and the 2,300 plus fixings were manufactured by them. The material used was aluminium bronze which offered strength together with resistance to corrosion and fatigue.<br />
<br />
<b>The mullion structure</b><br />
Steel was chosen for the main mullion structure on account of its strenght and stiffness. The standard mullions were fabricated from two parallel 90mm diameter tubes at 530mm centres joined by a 6mm plate web. This section had the advantage that the geometry could be solved along the centre line of the outer chord and standard connection details could be developed that would apply to the whole range of orientations that would occur.<br />
<br />
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/-rfwkEUw6wcI/T8KY8b2PTtI/AAAAAAAAAlQ/SWy-yeWwGa0/s1600/Mullion+and+glass+structural+detail,+Sydney+Opera+House.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="640" src="http://3.bp.blogspot.com/-rfwkEUw6wcI/T8KY8b2PTtI/AAAAAAAAAlQ/SWy-yeWwGa0/s640/Mullion+and+glass+structural+detail,+Sydney+Opera+House.png" width="614" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Mullion and glass structural details as built, Sydney Opera House.</td></tr>
</tbody></table>
<br />
One of the critical details of each of the walls was the method of connecting the mullions to the shells at their top edge. The position of cables in the pre-stressed ribs prohibited any form of drilling into the rib to make a fixing. Luckily, during the design of the shells certain ribs had been chosen to support the glass walls, which were strengthened and had extra holes cast into them. These holes did not coincide with the position of the mullions and it as therefore decided to cast on to the rib a strip of in situ concrete.<br />
<br />
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://4.bp.blogspot.com/-MRnyn3PwBvY/T8KbuYmNi0I/AAAAAAAAAlc/Fx3S4Yc9m7c/s1600/Mullions+top+fixing+to+the+corbels.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="484" src="http://4.bp.blogspot.com/-MRnyn3PwBvY/T8KbuYmNi0I/AAAAAAAAAlc/Fx3S4Yc9m7c/s640/Mullions+top+fixing+to+the+corbels.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Mullions top fixing to the corbels, and installation of ties between mullions.</td></tr>
</tbody></table>
<br />
No two corbels are identical, nor is the interval between corbels constant, and in situ concrete was therefore the most suitable material.<br />
<br />
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://4.bp.blogspot.com/-CCH2kpC2BYs/T8KcRg2Mt7I/AAAAAAAAAlk/YEndWckGmxU/s1600/Imagen+3.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="422" src="http://4.bp.blogspot.com/-CCH2kpC2BYs/T8KcRg2Mt7I/AAAAAAAAAlk/YEndWckGmxU/s640/Imagen+3.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Process of fixing mullions on site with scaffoldings. A4 wall.</td></tr>
</tbody></table>
<br />
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://4.bp.blogspot.com/-xzqsrmJ3IiE/T8Kcj_jgpbI/AAAAAAAAAls/SPhh3MH2iys/s1600/Connection+between+top+and+bottom+mullion.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="640" src="http://4.bp.blogspot.com/-xzqsrmJ3IiE/T8Kcj_jgpbI/AAAAAAAAAls/SPhh3MH2iys/s640/Connection+between+top+and+bottom+mullion.png" width="404" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Coonection between top and bottom mullion</td></tr>
</tbody></table>
The mullions were fabricated in two sections, one for the top cylinder, the other for the upper and lower cones. The upper sections are bolted to the corbels and tied back at the bottom by struts to the rear wall of the auditorium. The lower sections are bolted to the upper sections and are supported at the lower end by trusses suported, in turn, by V-colums on the podium.<br />
<br />
The result of this process was to liberate a wide inner space at the floor level, both at the entrance and at the back side of the auditoria, thus providing a much required space for internal circulation, as can be seen in the image below. I am still impressed with the lightness of the structural concept considering the large spans and the loads. A real feat!<br />
<br />
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://4.bp.blogspot.com/-lYvlGhF3TRQ/T8KdW7FoscI/AAAAAAAAAl0/wvnhfuiQP0I/s1600/The+foyer+at+A4+seen+from+inside.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="500" src="http://4.bp.blogspot.com/-lYvlGhF3TRQ/T8KdW7FoscI/AAAAAAAAAl0/wvnhfuiQP0I/s640/The+foyer+at+A4+seen+from+inside.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">The foyer at A4 (Concert Hall) seen from inside. The V-columns support a line of flat edge trusses where the mullions sit.</td></tr>
</tbody></table>
<br />
<b>Sealing and waterproofing - more problems</b><br />
There is no space here to detail the research conducted by John Hooper from Arup on laminated glass under sustained load, the geometrical calculations and structural analysis using computer programmes - the first ones on facade elements that I have notice - or the clever method devised for shaping laminated glass sheets to fit the varied dimensions. All this can be read at the <i>Arup Journal</i> article from October 1973.<br />
<br />
My last note will be on a nowadays quite standard detail, silicone sealing, that was rather new at the time and created much confusion when problems arose during glass installation. With much of the glass inclined to the almost horizontal and located above public spaces, it was particularly important that the walls should be completely watertight. Use of the best available type of sealant was essential, and silicone rubber by Rhône-Poulenc (translucent type) was selected for this purpose.<br />
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right; margin-left: 1em; text-align: right;"><tbody>
<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/-lZvgDRWrw-U/T8KlPpvr3fI/AAAAAAAAAmI/wOPQoyn5zWk/s1600/Imagen+4.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="640" src="http://3.bp.blogspot.com/-lZvgDRWrw-U/T8KlPpvr3fI/AAAAAAAAAmI/wOPQoyn5zWk/s640/Imagen+4.png" width="405" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Installing glass with suction cups and a crane.<span class="Apple-style-span" style="font-size: small;"> </span></td></tr>
</tbody></table>
<div class="separator" style="clear: both; text-align: center;">
</div>
The choice of silicone rubber was really dictated by the presence of the horizontal glass-to-glass butt joints. These joints are directly exposed to the atmosphere and silicone rubber, besides having an excellent adhesion to glass, has a high resistance to ultra-violet radiation and other weathering agents.<br />
<br />
Silicone rubber, being a one-part sealant, is relatively easy to apply; compressed air guns were used on site as the image below shows. However, it is crucial that the substrates have to be cleaned and prepared to quite stringent standards.<br />
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<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/--z-tljw8MI8/T8KmBUfcxwI/AAAAAAAAAmY/2zlYUr0oXPI/s1600/Imagen+5.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="432" src="http://3.bp.blogspot.com/--z-tljw8MI8/T8KmBUfcxwI/AAAAAAAAAmY/2zlYUr0oXPI/s640/Imagen+5.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Silicone being applied to the extruded bronze T-joint before installation of the glazing bar.</td></tr>
</tbody></table>
<br />
Approximately a month after the first sealing was complete in the A4 wall, it was noticed that the sealant was separating from the bronze glazing bar. The most likely reason appeared to be poor preparation of the bronze work, or atmospheric contamination prior to sealing. The faulty material was cut out, a series of site tests conducted and the areas resealed. It soon became evident that the problem was much more serious than anticipated: it was almost impossible to achieve a permanent adhesion of silicone to bronze which could withstand water immersion.<br />
<br />
The manufacturers were consulted, other primers were tested and gradually a successful technique was evolved. The problem appeared to be that the silicone joint as designed was too deep in relation to its width. The volume of silicone on the joint was excessive in relation to the free surface area from which acetic acid - generated during the curing - could disperse. The acetic acid was able to attack the bronze through the primer, and the product of this action dissolved out when the joint was immersed.<br />
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<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/-IBEqGDEovaI/T8Kk8SwnsUI/AAAAAAAAAmA/9hJwIbKfsbQ/s1600/Imagen+2.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="424" src="http://3.bp.blogspot.com/-IBEqGDEovaI/T8Kk8SwnsUI/AAAAAAAAAmA/9hJwIbKfsbQ/s640/Imagen+2.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Cleaning and protecting the joints from dust prior to silicone sealing.</td></tr>
</tbody></table>
<div class="separator" style="clear: both; text-align: center;">
<a href="http://1.bp.blogspot.com/-mOeyH-88AME/T8KqVWKKTeI/AAAAAAAAAmk/aCCwcJ0Z2uE/s1600/Imagen+17.png" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="400" src="http://1.bp.blogspot.com/-mOeyH-88AME/T8KqVWKKTeI/AAAAAAAAAmk/aCCwcJ0Z2uE/s400/Imagen+17.png" width="313" /></a></div>
The cross section of the joint was changed to allow a greater surface area of sealant relative to the volume, to facilitate dispersion of acetic acid, and the method of clamping the cover strip down on to the sealant was introduced. More time also had to be allowed for curing of the primers before the silicone was applied and much more time given for the silicone to cure and the generated acetic acid to disperse, before the cover strip was placed.<br />
<br />
It also proved important to protect the joint from water until curing was complete. To do this, strips of polythene were sealed down to the glass, covering the joint, and they remained there until the scaffolding was removed. The joint as finally perfected remained watertight, quite independently of adhesion between silicone and bronze, as initially expected...<br />
<br />
<b>Final code</b><br />
My intention when I started this long post was to answer a number of questions. The answers should be clear by now:<br />
<br />
<ul>
<li><i>Are the glazed walls at least partly Utzonian?</i> Yes they are: a look at the competition section from 1956 is not too dissimilar to the final design, and Utzon's main requirements were met by Peter Hall and his team. </li>
<li><i>Who were their designers? </i>A bunch of architects and engineers, but the main credits should go to Hall, Lewis, Croft and Hooper. </li>
<li><i>Was it a smooth process or was it another nightmare within the general conundrum of the job?</i> Croft provided an accurate answer for this, quoted above. </li>
<li><i>And finally, is there anything we can learn from the Sydney Opera House glass walls? </i>Our old man, Ove Arup, provided a general answer that fits here perfectly well: "We have realised that only intimate integration of the various parts or the various disciplines will produce the desired results". Amen.</li>
</ul>
<br />
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/-j9h7gcX2lDQ/T8KvL7bzqGI/AAAAAAAAAmw/YLqEakmR0tE/s1600/Imagen+13.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="428" src="http://1.bp.blogspot.com/-j9h7gcX2lDQ/T8KvL7bzqGI/AAAAAAAAAmw/YLqEakmR0tE/s640/Imagen+13.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Ove Arup</td></tr>
</tbody></table>
As usual in these posts, a last paragraph should go to leave track of the suppliers, manufacturers and contractors involved in the building of the Sydney Opera House glass walls. Here they are:<br />
<br />
<ul>
<li>Main contractor, M. R. Hornibrook Pty Ltd. </li>
<li>Steelwork for the glass walls, J. W. Broomhead Pty Ltd. </li>
<li>Metalwork and installation, Permasteel Pty Ltd. (yes, these are the guys that later would join the Italian company Isa to become the world-known façade contractor Permasteelisa). </li>
<li>Fixings, Hawker de Havilland Pty Ltd. </li>
<li>Sawing machinery and glass handling equipment, Quick-steel Engineering Pty Ltd. </li>
<li>Glass cutting and installation, VASOB Glass Pty Ltd. </li>
<li>Bronze extrussions supply: Austral Bronze Crane Copper Pty Ltd. </li>
<li>Glass supply, Boussois Souchon Neuvesel + Société Industrielle Triplex. </li>
<li>Sealant: Rhône-Poulenc.</li>
</ul>
<br />
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<div class="separator" style="clear: both; text-align: center;">
<a href="http://1.bp.blogspot.com/-QKrWmGdIdmg/T8suYjTxY_I/AAAAAAAAApU/yfcosR_L2YY/s1600/Perma+logo.png" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" src="http://1.bp.blogspot.com/-QKrWmGdIdmg/T8suYjTxY_I/AAAAAAAAApU/yfcosR_L2YY/s1600/Perma+logo.png" /></a></div>
If all suppliers and installers kept their contribution to the construction of the Sydney Opera House with great pride, <a href="http://www.permasteelisagroup.com/" target="_blank">Permasteelisa</a> is probably the company that took it more deeply. Their company logo (left) is a schematic elevation of the A4 gable end. Massimo Colomban from Permasteelisa likes to mention the new technologies applied in large scale in this job for the first time. He is probably right on two of them: these were the first large suspended glass walls and laminated glass was used here in large - and in deep - for the first time. Colomban adds that this was also the first example of extended use of structural silicon glazing. This is not right as we have seen; glass is mechanically fixed at the large sides and it is bottom supported on pins. He probably has been told about the conundrum of the silicone application and how some lessons were taken from it; but complex as it came out this was just weatherproof sealing, not structural sealing.<br />
<br />
I can't resist the temptation of adding a selection of images about the details, construction or final impression of the glass walls, that I found interesting but have not been able to place in the text above. Here they are.<br />
<br />
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/-5AY74XEgs5k/T8KvjhiBz2I/AAAAAAAAAm4/5OY-Drw7w2M/s1600/Imagen+6.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="432" src="http://2.bp.blogspot.com/-5AY74XEgs5k/T8KvjhiBz2I/AAAAAAAAAm4/5OY-Drw7w2M/s640/Imagen+6.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Installing the inclined glass pieces overlooking the harbour at A4. 1972.</td></tr>
</tbody></table>
<br />
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/-VICmZu3La1E/T8Kv72KMbHI/AAAAAAAAAnA/YDBGV9pGVd0/s1600/Imagen+8.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="380" src="http://3.bp.blogspot.com/-VICmZu3La1E/T8Kv72KMbHI/AAAAAAAAAnA/YDBGV9pGVd0/s640/Imagen+8.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Aerial view of B4 (left) and A4 (right) glass walls almost finished. 1972.</td></tr>
</tbody></table>
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://4.bp.blogspot.com/-lqcyXmJYqUo/T8KwW_vea6I/AAAAAAAAAnI/twyIKZ-gW2w/s1600/Imagen+10.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="426" src="http://4.bp.blogspot.com/-lqcyXmJYqUo/T8KwW_vea6I/AAAAAAAAAnI/twyIKZ-gW2w/s640/Imagen+10.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">A4 from inside. Glass was already installed when the picture was taken.</td></tr>
</tbody></table>
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/-J7V69zJ0P-E/T8KwqDVvR8I/AAAAAAAAAnQ/Pjq5z-VNU3g/s1600/Imagen+12.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="422" src="http://3.bp.blogspot.com/-J7V69zJ0P-E/T8KwqDVvR8I/AAAAAAAAAnQ/Pjq5z-VNU3g/s640/Imagen+12.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">A4 from inside. Total transparency, no transoms.</td></tr>
</tbody></table>
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://4.bp.blogspot.com/-zVNM1hI9je4/T8Kw4u5AaZI/AAAAAAAAAnY/xN9gPmI-7GA/s1600/Imagen+14.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="636" src="http://4.bp.blogspot.com/-zVNM1hI9je4/T8Kw4u5AaZI/AAAAAAAAAnY/xN9gPmI-7GA/s640/Imagen+14.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">South side: connection between the glass wall and the ribs.</td></tr>
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<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/-5wwiFWxTRzw/T8KxOcQ93sI/AAAAAAAAAng/PJndC9xR9Fc/s1600/Imagen+16.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="394" src="http://2.bp.blogspot.com/-5wwiFWxTRzw/T8KxOcQ93sI/AAAAAAAAAng/PJndC9xR9Fc/s640/Imagen+16.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Nose detail between the almost flat glass roof and the bottom glazed strip. Restaurant.</td></tr>
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<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/-oHec5V8BqEs/T8KxlpdRE-I/AAAAAAAAAno/9TegbTxZP1w/s1600/Imagen+18.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="640" src="http://3.bp.blogspot.com/-oHec5V8BqEs/T8KxlpdRE-I/AAAAAAAAAno/9TegbTxZP1w/s640/Imagen+18.png" width="342" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Sill detail, infill glass wall to sides or bottom of shells</td></tr>
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<tr><td style="text-align: center;"><a href="http://4.bp.blogspot.com/-8Y7MDKQeIpo/T8KyPKKI9VI/AAAAAAAAAnw/xibUsDDvzUM/s1600/Imagen+21.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="298" src="http://4.bp.blogspot.com/-8Y7MDKQeIpo/T8KyPKKI9VI/AAAAAAAAAnw/xibUsDDvzUM/s640/Imagen+21.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Longitudinal section through Concert Hall. A4 to the left, A1 to the right.</td></tr>
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<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/-HmUkMfQ-aVs/T8KyhzSrZ6I/AAAAAAAAAn4/HKSW5wglAYU/s1600/Imagen+20.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="268" src="http://3.bp.blogspot.com/-HmUkMfQ-aVs/T8KyhzSrZ6I/AAAAAAAAAn4/HKSW5wglAYU/s640/Imagen+20.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Longitudinal section through Theatre Hall. B4 to the letf, B1 to the right.</td></tr>
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<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/-O0xiLsHjzFU/T8Ky1lhq2vI/AAAAAAAAAoA/LZnxhWzcwIw/s1600/Imagen+22.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="250" src="http://2.bp.blogspot.com/-O0xiLsHjzFU/T8Ky1lhq2vI/AAAAAAAAAoA/LZnxhWzcwIw/s640/Imagen+22.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">West elevation of Concert Hall. All the black areas are glass walls.</td></tr>
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<tr><td style="text-align: center;"><a href="http://4.bp.blogspot.com/-qvMNw2siXlQ/T8KzIfaLRDI/AAAAAAAAAoI/p3QUxmE1dyo/s1600/Imagen+15.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="280" src="http://4.bp.blogspot.com/-qvMNw2siXlQ/T8KzIfaLRDI/AAAAAAAAAoI/p3QUxmE1dyo/s640/Imagen+15.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">North elevation of the Theatre (left) and Concert (right) Halls.</td></tr>
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<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/-KNSIoP7THEc/T8Kz6vTl1pI/AAAAAAAAAoQ/8KiK--otCa0/s1600/Foyer_Opera_Theatre_SHO.jpg" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="426" src="http://3.bp.blogspot.com/-KNSIoP7THEc/T8Kz6vTl1pI/AAAAAAAAAoQ/8KiK--otCa0/s640/Foyer_Opera_Theatre_SHO.jpg" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Foyer at the North side of the Theatre Hall.</td></tr>
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<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/-nCrIwgblzcQ/T8K0PeRoliI/AAAAAAAAAoY/uZvVvaiGwXQ/s1600/Imagen+1.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="458" src="http://1.bp.blogspot.com/-nCrIwgblzcQ/T8K0PeRoliI/AAAAAAAAAoY/uZvVvaiGwXQ/s640/Imagen+1.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">The restaurant seen from the concourse.</td></tr>
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<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/-nMHZ_XAQ8JY/T8K0cg--z4I/AAAAAAAAAog/EllpD6VMXL8/s1600/Imagen+2.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="462" src="http://1.bp.blogspot.com/-nMHZ_XAQ8JY/T8K0cg--z4I/AAAAAAAAAog/EllpD6VMXL8/s640/Imagen+2.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">The side walls of the Concert Hall.</td></tr>
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<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/-qIfltp2iyKI/T8K0sUeJYYI/AAAAAAAAAoo/v1g3dkkLJZk/s1600/Imagen+5.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="426" src="http://2.bp.blogspot.com/-qIfltp2iyKI/T8K0sUeJYYI/AAAAAAAAAoo/v1g3dkkLJZk/s640/Imagen+5.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Restaurant, Concert Hall and Theatre Hall at night.</td></tr>
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<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/-CGNXNTLaX0k/T8K1ASqbA8I/AAAAAAAAAow/AqLbWtjet1k/s1600/SOH+Opera+Theatre+south+wall.jpg" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="640" src="http://2.bp.blogspot.com/-CGNXNTLaX0k/T8K1ASqbA8I/AAAAAAAAAow/AqLbWtjet1k/s640/SOH+Opera+Theatre+south+wall.jpg" width="426" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Theatre Hall at sunset.</td></tr>
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<br />Ignacio Fernández Sollahttp://www.blogger.com/profile/03918193520738485621noreply@blogger.com94tag:blogger.com,1999:blog-1298203288964657974.post-9520712752010756932012-05-13T20:35:00.000+02:002012-05-14T08:18:00.290+02:00A quest for thick glazed façadesAfter decades of glass thickness reduction and transparency in glazed façades, a whirl of glass translucency and weight is taking the architectural scene. You may have found it already in small places: building entrances, sculptures and the like. But the quest for thick, icy blocks of glass stacked in façades is here to stay, or at least that's my impression.<br />
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This post will discuss origins and directions of the 'thick glass' trend.<br />
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<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/-_4k6zJemfLs/T6w8DhQXG2I/AAAAAAAAAbA/Z-Nigw2Mkmw/s1600/Lawrie+GE+glass+detail.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="356" src="http://3.bp.blogspot.com/-_4k6zJemfLs/T6w8DhQXG2I/AAAAAAAAAbA/Z-Nigw2Mkmw/s640/Lawrie+GE+glass+detail.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">GE Building glazed entrance detail, seen from inside. Designed by Lee Lowry, 1933-34</td></tr>
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Inspiration for this story came by chance during a visit to New York City some months ago. The main building at <a href="http://www.greatbuildings.com/buildings/Rockefeller_Center.html" target="_blank">Rockefeller Center</a> - RCA tower, now called GE Building - has a decorated main entrance finished in 1934 that called my attention. The top part of the entrance shows three stone low-relief panels conmemorating the spirit of the radio, named "Wisdom, Sound and Light" (see image below).<br />
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Sculpted by <a href="http://en.wikipedia.org/wiki/Lee_Lawrie" target="_blank">Lee Lawrie</a>, the imposing central panel showing a bearded Wisdom figure, today an art deco icon, can be clearly seen from Fifth Avenue. But the top limestone pieces are only part of the story.<br />
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<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/-gvnlnqh1v-k/T6w8Wv9wKtI/AAAAAAAAAbI/mGlTrXuJXpY/s1600/Lee+Lawrie+GE+entrance.jpg" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="440" src="http://3.bp.blogspot.com/-gvnlnqh1v-k/T6w8Wv9wKtI/AAAAAAAAAbI/mGlTrXuJXpY/s640/Lee+Lawrie+GE+entrance.jpg" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">GE Building entrance at the Rockefeller Center - stone and glass low-relief by Lee Lawrie, 1933-34. You can identify Wisdom at the top centre, Sound at the left and Light at the right hand.</td></tr>
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With golden rays crowning his head, Wisdom's right hand clutches a golden compass that measures the cosmic forces swirling in the 15 x 55 feet glass blocks screen below. Here comes the magic. Made of 240 glass blocks carved in cast Pyrex, the screen is a technical and artistic masterpiece.<br />
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<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/-2qAAnN3eG2E/T6w8qZ6eZgI/AAAAAAAAAbQ/m4V8Ta7g228/s1600/Attila+Piccirilli+636+Fifth+Avenue+2.jpg" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="400" src="http://2.bp.blogspot.com/-2qAAnN3eG2E/T6w8qZ6eZgI/AAAAAAAAAbQ/m4V8Ta7g228/s400/Attila+Piccirilli+636+Fifth+Avenue+2.jpg" width="265" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Piccirilli's "Youth leadind Industry" at 636 5th Ave</td></tr>
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The glazed bas-relief is a translucent wall of rectangular glass pieces (around 700 x 450 mm each), tied at their back to vertical bronce stripes, with a delicate front texture: calmed at the edges of the screen, agitated in the central axis below the moving compass. The attached images (see below) provide a pale impression of its contrasts: thick but slender, translucent from inside but almost opaque from outside, half part of a door and half part of a sculpture. </div>
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Lee Lawrie was not the only artist using cast glass at the Rockefeller Center in the thirties. If you compare Lawrie's magnificent glazed entrance with Attilio Piccirilli's "Youth leading Industry" (see at left, finished in 1936) the contrast is clear. Piccirilli's glass low relief adorns the entrance of the International Building at 636 Fifth Avenue. Lit from behind but opaque if seen from the inside hall, it remains an evening spectacle on Fifth Ave. Piccirilli's bas-relief was cast in 45 Pyrex glass blocks, each hand-cast and different.<br />
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Good enough, but we will probably agree that Piccirilli's screen is merely decoration, not architecture. Glass here could have been marble and it would remain rather similar. That is not the case with Lawrie's screen, where glass and transparency go hand in hand as the following images taken from inside testify. </div>
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<a href="http://1.bp.blogspot.com/-k4pkcvgMrBQ/T6w9Up7tm8I/AAAAAAAAAbg/fpRGWDX1Acg/s1600/Lawrie+GE+from+inside+1.JPG" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="480" src="http://1.bp.blogspot.com/-k4pkcvgMrBQ/T6w9Up7tm8I/AAAAAAAAAbg/fpRGWDX1Acg/s640/Lawrie+GE+from+inside+1.JPG" width="640" /></a></div>
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<a href="http://1.bp.blogspot.com/-zigVmLcMzzM/T6xAEwcjO1I/AAAAAAAAAb4/gIizjpA0K3Q/s1600/Lawrie+GE+combined.png" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="436" src="http://1.bp.blogspot.com/-zigVmLcMzzM/T6xAEwcjO1I/AAAAAAAAAb4/gIizjpA0K3Q/s640/Lawrie+GE+combined.png" width="640" /></a></div>
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<a href="http://1.bp.blogspot.com/-pNvaPzIntZ4/T6w9khSJqeI/AAAAAAAAAbo/NWTwoWgaus0/s1600/Lawrie+GE+from+inside+4.JPG" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="432" src="http://1.bp.blogspot.com/-pNvaPzIntZ4/T6w9khSJqeI/AAAAAAAAAbo/NWTwoWgaus0/s640/Lawrie+GE+from+inside+4.JPG" width="640" /></a></div>
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<tr><td class="tr-caption" style="text-align: center;">Top to bottom: details of the glazed wall at the Rockefeller GE Building entrance. All taken from inside except the bottom right one.</td></tr>
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Seen from today Lawrie's glazed entrance is strikingly modern. In fact, a number of translucent massive facades could be linked to the images above. One of them, of course, is Rafael Moneo's <a href="http://people.seas.harvard.edu/~jones/lab_arch/moneo/kursaal/kursaal.html" target="_blank">Kursaal Auditorium</a> in San Sebastian.</div>
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The Kursaal Auditorium is the combination of two translucent, twisted and slightly angled glass cubes located by the seaside - two 'stranded rocks which perpetuate the geography and underline the harmony between the natural and the artificial'. The cubes have curved laminated glass walls which protect them from salt-laden sea winds. The outer skin, a laminated 19 mm extra-clear, sandblasted glass with an external 5 mm fluted printed glass, transmits light to the interior by day; at night the exterior is transformed into a mysterious light source. </div>
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<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/-GQY54pLAJUk/T61pQefM88I/AAAAAAAAAcM/NEAxRmwcwkU/s1600/Moneo+Kursaal+4.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="404" src="http://3.bp.blogspot.com/-GQY54pLAJUk/T61pQefM88I/AAAAAAAAAcM/NEAxRmwcwkU/s640/Moneo+Kursaal+4.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Kursaal San Sebastian (Rafael Moneo, 1990-1999). Main Auditorium building looking outside through one of the big windows.</td></tr>
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I like the view from inside the cubes (see above) because it explains the building concept better than the typical daylight external images. Of course there are differences with the GE building entrance. First in scale, then in layers: the Kursaal façade is a double skin wrapping the steel structure of the buildings. The outer skin is curved and fluted, the inner skin is flat. Both are slightly translucent to avoid direct vision of the encased steel structure.<br />
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<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/-63DWOa_eVRU/T69nThPy7sI/AAAAAAAAAcg/w0Km2QaabPg/s1600/Moneo+Kursaal+2.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="400" src="http://1.bp.blogspot.com/-63DWOa_eVRU/T69nThPy7sI/AAAAAAAAAcg/w0Km2QaabPg/s400/Moneo+Kursaal+2.png" width="297" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Kursaal San Sebastian. The curved glass facade.</td></tr>
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But there are a number of surprising similarities too. In both cases the glass grid is rectangular and horizontal, with continuous vertical joints - a stacked bond. The intention is not to read the facade as heavy masonry but as a light screen. Then the curvature: concave at the outside, flat at the inside. And finally the fixing system: a slender line of mullions from behind in both cases. Even the yellow light coming in is strikingly similar!</div>
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The images of the Kursaal facade during construction (see below) are as always very instructive. Isn't this Lawrie at a gigantic scale?</div>
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While I was working for Cupples - around 1992-93 - we visited Rafael Moneo at his studio in Madrid for this project. He was rightly obsessed with the quality of fluted glass he was looking after, and with the availability of suppliers for such a combination of fluting, lamination, extra-clarity, translucency and bending in glass. Cupples presented Moneo several glass samples and we prepared some façade details. The story moved on and finally Cricursa supplied the glass. The façade contractor was the Basque group Umaran, like Cupples a great but extinct dynosaur from the 20th century.</div>
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<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/-gbOnkS3sbx0/T61puUx95OI/AAAAAAAAAcU/3IGscevJTUA/s1600/Moneo+Kursaal+1.jpg" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="368" src="http://2.bp.blogspot.com/-gbOnkS3sbx0/T61puUx95OI/AAAAAAAAAcU/3IGscevJTUA/s640/Moneo+Kursaal+1.jpg" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Kursaal San Sebastian. Images of the double skin façade during construction.</td></tr>
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But Moneo's Kursaal use of glass is also an example of relative failure in translucency. Depending on the time of day and the sun position the structure behind the outer glass may become too obvious. In these occasions the visual impression is not of an ice block but of a thin veil: the game of scale is lost and the building fabric becomes too evident. The image below is one of those cases.<br />
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Thick glass can be more subtle and difficult to control that sheer transparency... but then, when is glass really transparent?<br />
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<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/-6EEzF6-7Phs/T6_KCkH0PSI/AAAAAAAAAcs/6pX6aQPk69w/s1600/Moneo+Kursaal+3.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="420" src="http://1.bp.blogspot.com/-6EEzF6-7Phs/T6_KCkH0PSI/AAAAAAAAAcs/6pX6aQPk69w/s640/Moneo+Kursaal+3.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Kursaal San Sebastian. Aluminium mullions and main structure appear behind translucent glass as seen from outside.</td></tr>
</tbody></table>
Let's go back to New York in our quest for iced glass blocks. 11 Times Square is a new office tower (opened in 2011) located right beside Renzo Piano's New York Times building. Waiting for the green light at 8th Ave with 41st Street I was surprised by the contrast between a tall, thin, mullion glass-supported transparent wall and a back-lit stacked glass wall beside. Both are part of the main lobby of this tower.<br />
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<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/-WbzYU6AQBpM/T6_PQK3OQ1I/AAAAAAAAAc4/MkPMAOuQb54/s1600/11+Times+Square+1.JPG" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="640" src="http://3.bp.blogspot.com/-WbzYU6AQBpM/T6_PQK3OQ1I/AAAAAAAAAc4/MkPMAOuQb54/s640/11+Times+Square+1.JPG" width="480" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">11 Times Square lobby seen from 41st Street, NYC. FXFowle Architects LLP.</td></tr>
</tbody></table>
If you came from a time travel - right from the seventies for instance - you would be surprised by the height of this transparent glass wall, standing still without any apparent aluminium or steel support. And it's really impressive, even today! But after the last two decades of structural glass walls we are used to see large glazed walls supported by glass fins with bolted stainless steel spiders as the only connecting points.<br />
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What called my attention in this case was the yellow glass wall to the left of the lobby: a back-lit translucent wall made with flat, vertically fluted glass blocks, stacked to provide a screen to support the building name and its tenants. It reminds us the facade of the Kursaal or Lawrie's cast glass, except that this one is opaque and flat. A detailed view can give us more clues. The whole glass lobby was commisioned to Gartner Steel and Glass, part of Permasteelisa Group, and completed in 2010.<br />
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The transparent part has a surface of 1,040 m2. The glass fins project out of the glass plan into the walkway and are 16.4 m in height, helped by an intermediate connection at a back slab located at 2/3 of their total height. The special stacked glass wall - this is all I found at Gartner's webpage - is 120 m2.<br />
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<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/-Pr8UG5Mwo2M/T6_XnbXP_4I/AAAAAAAAAdE/6Pt6pUOIvPg/s1600/11+Times+Square+stacked+glass+wall+lobby.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="418" src="http://2.bp.blogspot.com/-Pr8UG5Mwo2M/T6_XnbXP_4I/AAAAAAAAAdE/6Pt6pUOIvPg/s640/11+Times+Square+stacked+glass+wall+lobby.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">11 Times Square stacked glass wall at the lobby. Images from outside (left) and inside (right).</td></tr>
</tbody></table>
A detailed view will give us more information about our next icy translucent wall. It must be a laminated glass with the outer lite cast in vertical stripes. The thickness of the stripes is wider than the one at the Kursaal, but its flatness provides an impression of subtle weaving. As in San Sebastian the glass is retained by a grill of parallel, horizontal profiles: here they are in stainless steel, those at the Kursaal are made in cast aluminium. What a decision of a master builder: cast aluminium supporting cast glass!<br />
<br />
The stacked glass wall makes itself apparent in the evenings, when crowds rushing to attend Broadway plays mix with those running home from work. At this time the 'eleven' mark behind the glass becomes obvious and the tenants' names shine in darkness against the back-lit wall. Sadly, this is a sign of our times: gone are Wisdom and his colleagues; what matters now is company brand image...<br />
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<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/-nfu4gaCoWAo/T6_Yv7xXC7I/AAAAAAAAAdM/hCwo2LLDW8A/s1600/11+Times+Square+stacked+glass+wall+lobby+2.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="474" src="http://2.bp.blogspot.com/-nfu4gaCoWAo/T6_Yv7xXC7I/AAAAAAAAAdM/hCwo2LLDW8A/s640/11+Times+Square+stacked+glass+wall+lobby+2.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">11 Times Square tower. General image (left) and lobby from inside (right). The stacked glass is a screen supporting tenants' logos.</td></tr>
</tbody></table>
The list of recent 'thick glass' walls is endless and this post cannot be that long. From the examples above we have got a fair view of stacked, heavy laminated glass, but this is only one technique in many.<br />
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Let me list other techniques that are being used to obtain the impression - or the literality - of thick glass (some of the buildings listed here are shown right below):<br />
<ol>
<li><b>Fused glass</b>. A supplier of this technology is <a href="http://www.fusionglass.co.uk/" target="_blank">Fusion Glass Designs</a>, a brand of the British company <a href="http://www.chelsea-artisans.co.uk/" target="_blank">Chelsea Artisans</a>. One of their recent jobs is the <a href="http://www.fusionglass.co.uk/pdf_files/fgd-Louis_Vuitton_Singapore.pdf" target="_blank">Louis Vuitton shop</a> in Singapore, with kiln formed, curved and laminated glass. You can also look at this <a href="http://www.fusedglass.org/learn/what_is_fused_glass" target="_blank">webpage</a> for more info.</li>
<li><b>Molten cast glass</b>. This is the way U-glass (or channel glass) panels are made. The European main name in this technique is the German firm <a href="http://www.lamberts.de/en.html" target="_blank">Lamberts</a>, with the brand name <a href="http://www.linituk.com/index.html" target="_blank">Linit</a>, while its US counterpart (and business partner) is <a href="http://www.bendheimwall.com/" target="_blank">Bendheim Wall Systems</a>. The exemplary building with a U-glass cast facade is of course the Bloch Building at the <a href="http://www.archdaily.com/4369/the-nelson-atkins-museum-of-art-steven-holl-architects/" target="_blank">Nelson-Atkins Museum of Art</a> in Kansas City, a project of Steven Hall Architects finished in 2007.</li>
<li><b>Slumped cast glass</b>. Also called warm glass or kiln forming, a supplier of this technology is the British firm <a href="http://www.warm-glass.co.uk/" target="_blank">Warm Glass</a>.</li>
<li><b>Cast glass</b>. The general term; many of the examples here are somehow made of glass cast in a mould. A well-known supplier is <a href="http://www.castglass.com/" target="_blank">Castglass</a> and one of their recent jobs, the <a href="http://www.castglass.com/Diesel.html" target="_blank">Diesel store in NYC</a>, with cast glass molding in LED lighting. Another façade to visit is their <a href="http://www.castglass.com/Diesel.html" target="_blank">Glassworks Hot Shop</a> in Louisville Kentucky.</li>
<li><b>Pattern glass</b>. A general expression for laminated or printed glass where an intermediate layer or screen is added, creating the impression of pattern and providing translucency. A high-quality European supplier of this kind of glass is <a href="http://www.glasmarte.at/index_e.htm" target="_blank">GlasMarte</a> from Austria. They are the glass suppliers and façade contractors for Peter Zumthor's acclaimed translucent façade of the <a href="http://www.archdaily.com/107500/ad-classics-kunsthaus-bregenz-peter-zumthor/" target="_blank">Kunsthaus in Bregenz</a>. They also have an interesting glass point ceiling fitting system, named <a href="http://www.glasmarte.at/pdf/Folder/systeme-deckensysteme/index.html#/0/" target="_blank">GM Kub</a>. Worth having a look...</li>
<li><b>Recycled glass</b>. A new technique. When glass pieces coming from recycling are fused the result is a greenish, opaque panel with a promising application to façades. For most cases a 20mm thickness provides the required strength. See more at the British supplier <a href="http://www.greenhouseeffect.co.uk/facades.php" target="_blank">The Greenhouse Effect</a>.</li>
<li><b>Other techniques</b>, worth exploring if you are interested: glass billet, heavy laminated glass (the buildings presented above), carved glass, extruded rolled glass, textured glass...</li>
</ol>
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/-SwcV-XukYvs/T6_xvhK-JRI/AAAAAAAAAdY/3RmMHl5uPm8/s1600/Louis+Vuitton+facade+Singapore.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="434" src="http://2.bp.blogspot.com/-SwcV-XukYvs/T6_xvhK-JRI/AAAAAAAAAdY/3RmMHl5uPm8/s640/Louis+Vuitton+facade+Singapore.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">The Louis Vuitton facade in Singapore. Kiln-formed, laminated and curved 8+8mm glass.</td></tr>
</tbody></table>
<div>
</div>
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/-p3KAWfyy5R8/T6_ylUw5nFI/AAAAAAAAAdg/ArNt8vyQaPk/s1600/Nelson+Atkins+Museum+of+Art,+Kansas+City.jpg" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="320" src="http://3.bp.blogspot.com/-p3KAWfyy5R8/T6_ylUw5nFI/AAAAAAAAAdg/ArNt8vyQaPk/s640/Nelson+Atkins+Museum+of+Art,+Kansas+City.jpg" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Nelson Atkins Museum of Art, Kansas. Steven Hall architects. U-glass facade from Lamberts - Bendheim.</td></tr>
</tbody></table>
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/-wd4ZCVfCX9M/T6_zPI3bcMI/AAAAAAAAAdo/uMasA_66iIc/s1600/Nelson+Atkins+Museum+double+skin+facade+detail.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" src="http://1.bp.blogspot.com/-wd4ZCVfCX9M/T6_zPI3bcMI/AAAAAAAAAdo/uMasA_66iIc/s1600/Nelson+Atkins+Museum+double+skin+facade+detail.png" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Nelson Atkins Museum of Art; Steven Hall architects. Detail of the double skin facade with U-glass at the outer side.</td></tr>
</tbody></table>
<div>
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/-bwoakemhc2s/T7AlNep8RiI/AAAAAAAAAe8/XPN-w1yYlws/s1600/Kunsthaus+Bregenz+facade+3.jpg" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="416" src="http://3.bp.blogspot.com/-bwoakemhc2s/T7AlNep8RiI/AAAAAAAAAe8/XPN-w1yYlws/s640/Kunsthaus+Bregenz+facade+3.jpg" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Kunsthaus Bregenz, Peter Zumthor. Austria 1997. Etched translucent glass.</td></tr>
</tbody></table>
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/-cGoQO3U6xR4/T7Al1EzRjVI/AAAAAAAAAfE/r3AjiSTU6ME/s1600/Kunsthaus+Bregenz+facade+4.jpg" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="510" src="http://1.bp.blogspot.com/-cGoQO3U6xR4/T7Al1EzRjVI/AAAAAAAAAfE/r3AjiSTU6ME/s640/Kunsthaus+Bregenz+facade+4.jpg" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">The Kunsthaus at dawn with back-lighting.</td></tr>
</tbody></table>
We are entering a different ground here, that of glass as an artistic expression. But don't be afraid. If 'thick glass' in its many forms shall remain a trend for contemporary façades, there must be artists out there, chaps comparable to Lee Lawrie, from whose work we could get inspiration. You can find many names in this useful <a href="http://www.lamberts.de/en/links.html" target="_blank">link provided by Lamberts</a>. But if you wanted to meet only one name that must be Danny Lane, the best one to finish this post, an invitation to the artistic glass world.</div>
<div>
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<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://4.bp.blogspot.com/-i9b4w-v83dw/T6_3Y122RxI/AAAAAAAAAd0/XAm0G1J6A1U/s1600/Danny+Lane+4.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="432" src="http://4.bp.blogspot.com/-i9b4w-v83dw/T6_3Y122RxI/AAAAAAAAAd0/XAm0G1J6A1U/s640/Danny+Lane+4.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Danny Lane posing at his studio in London.</td></tr>
</tbody></table>
<div>
</div>
<div>
<a href="http://www.dannylane.co.uk/" target="_blank">Danny Lane</a> (born in 1955) is an American glass sculptor living and working in the UK. Lane’s work is monumental as much as physical; his stacked and fractured glass walls are in a transition zone between scupture and architecture. His London studio is equipped to create works of considerable scale, in glass and in steel. Glass furnaces enable Lane to create works of fluidity and brilliant colour as the ones selected below.<br />
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Go and visit his webpage for more. Please click the <i>Process</i> tab: you will learn how these glazed, iced pieces were made.</div>
<div>
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<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/-ymyczBqVyXo/T6_3sjHPvxI/AAAAAAAAAd8/gIF931RWOzQ/s1600/Danny+Lane+2.jpg" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="314" src="http://1.bp.blogspot.com/-ymyczBqVyXo/T6_3sjHPvxI/AAAAAAAAAd8/gIF931RWOzQ/s640/Danny+Lane+2.jpg" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Danny Lane, detail of stacked glass with a tensile rod.</td></tr>
</tbody></table>
<div>
<br />
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://4.bp.blogspot.com/-ujiXkSzqNtI/T6_4jewL1jI/AAAAAAAAAeE/8UfWwKAFCFQ/s1600/Danny+Lane,+Presence+of+seven.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="284" src="http://4.bp.blogspot.com/-ujiXkSzqNtI/T6_4jewL1jI/AAAAAAAAAeE/8UfWwKAFCFQ/s640/Danny+Lane,+Presence+of+seven.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Danny Lane, Presence of Seven. Allegheny College Pennsylvania USA (2002)</td></tr>
</tbody></table>
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/-oE7yR9shxQQ/T6_6ST-3OrI/AAAAAAAAAeM/DOeOpSVBm68/s1600/Danny+Lane+Stairway,+Sweden.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="498" src="http://3.bp.blogspot.com/-oE7yR9shxQQ/T6_6ST-3OrI/AAAAAAAAAeM/DOeOpSVBm68/s640/Danny+Lane+Stairway,+Sweden.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Danny Lane, Stairway. Borgholm Castle, Sweden (2005)</td></tr>
</tbody></table>
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/-LXnNRgGWAZE/T6_7FPt5fGI/AAAAAAAAAeU/EnQsYBhbikE/s1600/Danny+Lane,+Split+Prism.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="440" src="http://1.bp.blogspot.com/-LXnNRgGWAZE/T6_7FPt5fGI/AAAAAAAAAeU/EnQsYBhbikE/s640/Danny+Lane,+Split+Prism.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Danny Lane, Split Prism. San Francisco USA (2011)</td></tr>
</tbody></table>
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/-2a7YTwP9STk/T6_7qs26KNI/AAAAAAAAAec/6FNbd7kr1PQ/s1600/Danny+Lane+Borealis+1.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="436" src="http://1.bp.blogspot.com/-2a7YTwP9STk/T6_7qs26KNI/AAAAAAAAAec/6FNbd7kr1PQ/s640/Danny+Lane+Borealis+1.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Danny Lane, Borealis. General Motors HQ, Detroit USA (2005)</td></tr>
</tbody></table>
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/-3q537Ik6pek/T6_8BcTX9eI/AAAAAAAAAek/8ddvY9jMP70/s1600/Danny+Lane+Borealis+2.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="436" src="http://1.bp.blogspot.com/-3q537Ik6pek/T6_8BcTX9eI/AAAAAAAAAek/8ddvY9jMP70/s640/Danny+Lane+Borealis+2.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Danny Lane, Borealis detail. General Motors HQ, Detroit USA (2005)</td></tr>
</tbody></table>
</div>
<div>
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/-r-Y3Ji9OrPc/T7AUIIpruDI/AAAAAAAAAew/xwwI5c7WZGw/s1600/Danny+Lane,+Ice.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="424" src="http://3.bp.blogspot.com/-r-Y3Ji9OrPc/T7AUIIpruDI/AAAAAAAAAew/xwwI5c7WZGw/s640/Danny+Lane,+Ice.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Danny Lane, Ice. San Francisco USA (2011)</td></tr>
</tbody></table>
Is there materiality in glass? Plenty, as we have seen. Why then should we go only for the thin, transparent, ephemeral glass lites we have been using during the last century? Come on, cross the new frontier and be welcomed to the thick glass world...</div>
</div>
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<br /></div>Ignacio Fernández Sollahttp://www.blogger.com/profile/03918193520738485621noreply@blogger.com62tag:blogger.com,1999:blog-1298203288964657974.post-9597005147616891352012-04-19T22:18:00.014+02:002012-05-30T20:02:09.840+02:00Le Corbusier: a French lesson on 'Murs neutralisants'<span style="color: black; font-family: Tahoma, sans-serif; font-size: 10pt;"><span style="font-family: "Trebuchet MS", sans-serif;"></span></span><br />
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Is there still anything to discover about Corbu? Hidden inside his extensive writings - and sometimes evident in his projects - Le Corbusier seems to have individuated five building-physic concepts, were these his own developments or not:</div>
<ul>
<li><div class="MsoNormal" style="margin: 0cm 0cm 0pt;">
natural ventilation (aération naturelle) </div>
</li>
<li><div class="MsoNormal" style="margin: 0cm 0cm 0pt;">
natural lighting (éclairage solaire)</div>
</li>
<li><div class="MsoNormal" style="margin: 0cm 0cm 0pt;">
solar control (brise soleil)</div>
</li>
<li><div class="MsoNormal" style="margin: 0cm 0cm 0pt;">
thermally active facade in opaque or glazed walls (mur neutralisant)</div>
</li>
<li><div class="MsoNormal" style="margin: 0cm 0cm 0pt;">
internal air conditioning (respiration exacte)</div>
</li>
</ul>
These made for him part of "the modern techniques" (les techniques modernes). Funny they are precisely five points - but this is a coincidence...<br />
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://4.bp.blogspot.com/-812xWmHuyPE/T43hGpB-mUI/AAAAAAAAAZQ/ir78hmbDhe4/s1600/Natural+lighting+LC+01.png" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="226" src="http://4.bp.blogspot.com/-812xWmHuyPE/T43hGpB-mUI/AAAAAAAAAZQ/ir78hmbDhe4/s640/Natural+lighting+LC+01.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Sections showing sun lighting at the Zurich Sanatorium (left) and the skyscraper of Quartier La Marine (right). LC Ouvre Complete 1946-1952.</td></tr>
</tbody></table>
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://4.bp.blogspot.com/-sor7HeYWtYw/T43h2RmN-bI/AAAAAAAAAZY/c0fcpakUgns/s1600/Natural+ventilation+LC+01.png" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="198" src="http://4.bp.blogspot.com/-sor7HeYWtYw/T43h2RmN-bI/AAAAAAAAAZY/c0fcpakUgns/s640/Natural+ventilation+LC+01.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Ventilation scheme in standard houses for workers. Le Corbusier.</td></tr>
</tbody></table>
Corbu seems to have always paid attention to the first two items: natural ventilation and natural lighting, be it at his writings and in his projects (the images above are a good example). He was influenced by and a promoter of the hygienist culture of his time in architecture. But in the other three points he went beyond the usual and became the first modern architect really interested in mixing passive and active methods of energy control. Regardless the accuracy of his concepts from a physical point of view, this is a remarcable feat.<br />
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<a href="http://1.bp.blogspot.com/-Xfj7niCTkx8/T5B3m2IOg3I/AAAAAAAAAaw/EJ07NKfDvGk/s1600/Corbu.png" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="400" src="http://1.bp.blogspot.com/-Xfj7niCTkx8/T5B3m2IOg3I/AAAAAAAAAaw/EJ07NKfDvGk/s400/Corbu.png" width="290" /></a></div>
Seen from today's distance, Le Corbu was a prophet not only in architectural language and urbanism but also in identifying the importance of a right combination between building design (passive measures, mass, ventilation etc) and active systems (air control and mechanical distribution) for achieving comfort in buildings. But his strength as prophet may be precisely in his weaknesses as master builder. Had Le Corbusier had a rigurous technical knowledge in the five points above, his predictions would not have been as telling for the coming generations as they were. <br />
<br />
The two active concepts - the latter of the five, which Corbu developed between 1926 and 1933 - were the 'Mur neutralisant' and the 'Respiration exacte'. In my opinion, Corbu had it clear that both were intended to work together because they were complementary. Corbu tried to implement them at the Cité de Refuge in Paris and the Centrosoyuz in Moscow, unsuccessfully in both cases. Put simply, his intention was to obtain an internal comfortable environment all year round and in all climates.<br />
<br />
Corbu coined two names but in fact three aspects were required simultaneously:<br />
<ol>
<li>A very high air-tightness through the envelopes - hence the idea of sealed glass (or sealed opaque walls) being part of the 'Mur neutralisant' concept. The intention was -rightly - to avoid air and heat flowing from inside to outside and viceversa.</li>
<li>A mechanical system of controlled ventilation capable of adjusting both air temperature and humidity - that is, a rough description of an air conditioning system. This was the idea behind the 'Respiration exacte', which in fact comes from his colleague the engineer Gustave Lyon.</li>
<li>Finally, in order to allow glazed facades to act as external thermal envelopes, an active device that neutralized energy flows (both in winter and in summer) through glazed surfaces: the 'Mur neutralisant'. This acted mainly as a barrier avoiding heat to flow inside-out during winter and outside-in during summer. Corbu delevoped an existing, earlier device (water heat radiators installed between two parallel glazed walls) into a more ambitious idea. By inserting air pipes around a sealed double glazed cavity he suggested that treated air could be blowed, warm in winter and cold in summer, so as to neutralize the outer conditions. This would allow the 'Respiration exact' system to maintain a constant internal temperature of 18ºC.</li>
</ol>
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/-T8E_0DWC9fA/T5BuLtRPecI/AAAAAAAAAZ4/GQza0kAkr_Q/s1600/Respiration+exacte+schemes.png" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="316" src="http://2.bp.blogspot.com/-T8E_0DWC9fA/T5BuLtRPecI/AAAAAAAAAZ4/GQza0kAkr_Q/s640/Respiration+exacte+schemes.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Respiration exacte and Mur neutralisant as they were envisaged for the Centrosoyuz project in Moscow</td></tr>
</tbody></table>
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<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/-VEegfuhtKLg/T8Zepb69NMI/AAAAAAAAAo8/v6mbdn4qY0Y/s1600/Corbu+scheme+mur+neutralisant.jpg" imageanchor="1" style="clear: left; cssfloat: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="640" rba="true" src="http://2.bp.blogspot.com/-VEegfuhtKLg/T8Zepb69NMI/AAAAAAAAAo8/v6mbdn4qY0Y/s640/Corbu+scheme+mur+neutralisant.jpg" width="472" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">'Mur neutralisant' and 'Respiration exacte' diagram, 1929, as published in 'Précisions'</td></tr>
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Where did these ideas come from? Were they revolutionary or not? The 'Respiration exacte' concept seems to be a somewhat poetic version of the mechanical ventilation system used by Gustave Lyon at the Pleyel Theatre and in other French auditoria. It seems that Lyon called his system 'Aération ponctuelle', not so different from 'Respiration exacte'. In his drawings (see below) for the Centrosoyuz project in Moscow Corbu used the engineer's name in some of the details: "Aération ponctuelle. 80 litres-minute d'air à 18ºC par personne avec régénération dans circuit fermé; système Gust. Lyon" (Point ventilation. 80 litres/minute of air at 18ºC per person with regeneration in closed circuit; system Gust. Lyon).<br />
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/-WVeEMhkpVn4/T41StRaIYwI/AAAAAAAAAZA/gn6EefeB4l8/s1600/Centrosoyus+detail.png" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="340" nda="true" src="http://1.bp.blogspot.com/-WVeEMhkpVn4/T41StRaIYwI/AAAAAAAAAZA/gn6EefeB4l8/s640/Centrosoyus+detail.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Image of the Centrosoyuz project for Moscow with references to the Mur Neutralisant and the Aération Ponctuelle (1928)</td></tr>
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<br />
Lyon himself was not a mechanical engineer but an specialist in acoustics - to be precise, an expert in piano sound and its mechanisms. It seems that he entered the area of mechanical ventilation after having designed the acoustics for many concert halls, and probably having experienced the discomfort of those closed unventilated spaces. But he was not a climate engineer as Willis Carrier or the men at the American Blower Company. His intuitions on air conditioning came from his practical experience at improving the ventilation of the Salle Pleyel or the Trocadero Palace after he had gained reputation as an acustician. Lyon was 70 years old in 1927 at the opening of the Salle Pleyel in Paris: not exactly an eager engineer in contact with the novelties from New York or Chicago. In any case, the idea of an enclosed inner space - sealed from the outside - with some mechanical devices to control air temperature and humidity was not new, and it could very well be passed from Monsieur Lyon to his young new client, l'architecte Charles Eduard Jeanneret (Corbu).<br />
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<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/-bI-HFfZ0J1o/T5BxH1-Dj5I/AAAAAAAAAao/zMyB_yzYJ_M/s1600/Centrosoyuz+plan.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="226" src="http://1.bp.blogspot.com/-bI-HFfZ0J1o/T5BxH1-Dj5I/AAAAAAAAAao/zMyB_yzYJ_M/s640/Centrosoyuz+plan.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Centrosoyuz plan and external view. Notice the double glazed wall with sliding windows.</td></tr>
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<div>
In relation to the 'Mur neutralisant', I fully agree with Reyner Banham's position at his legendary book "<a href="http://www.amazon.com/Architecture-Well-Tempered-Environment-Reyner-Banham/dp/0226036987" target="_blank">The architecture of the well-tempered environment</a>". Le Corbusier had experienced a similar concept for the windows in his Villa Schwob in Switzerland by 1916, so that this seems to be his own development. In the Ville Schwob very large windows (one of them two storeys high, see below) were designed in two layers, with heating pipes between them, to prevent down draughts. In t he same details for the Centrosoyuz (1929) he referred to them as "Murs neutralisants de verre ou de pierre; circuit fermé rapide d'air sec chaud (hiver) ou froid (été); systéme L.C. - P.J." (Neutralising walls in glass or stone; quick closed circuit of dry hot air (winter) or cold (summer); system Le Corbusier - Pierre Jeanneret). The 'Mur neutralisant' was his baby; the 'Respiration exacte' was Lyon's.<br />
<br />
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/-JJeWcTLmq0o/T5BukqM8ESI/AAAAAAAAAaA/x86BC94FVXI/s1600/Villa+Schwob+outside-inside.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="220" src="http://3.bp.blogspot.com/-JJeWcTLmq0o/T5BukqM8ESI/AAAAAAAAAaA/x86BC94FVXI/s640/Villa+Schwob+outside-inside.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Villa Schwob, La Chaux de Fonds 1916. Notice the large window pane above the garden entrance: this was a double glass with an intermediate radiator system.</td></tr>
</tbody></table>
<br />
<br />
The glass solution was typical to the other Corbu 'Mur neutralisant' schemes; that for the opaque walls in Centrosoyuz reveals another great Corbu's intuition. An enclosed air cavity between two walls of pink tufa stone from the Caucasus (a volcanic, porous stone) would have been a very adequate thermal solution for opaque walls in Moscow, even if there was no hot air circuits inside. The Russian client ultimately dismissed the 'Mur neutralisant' system because of the lack of technical justification. At least they kept the double glazed wall, of which there were some previous examples built in Moscow (see the images of Zuyev Workers Club right below, a project by Ilya Golosov finished in 1926).<br />
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://4.bp.blogspot.com/--TZjZwsMXx4/T43jDtaxlzI/AAAAAAAAAZg/1lCSdLHWcK4/s1600/Zuyev+Workers+Club,+Moscow+1926.png" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="316" src="http://4.bp.blogspot.com/--TZjZwsMXx4/T43jDtaxlzI/AAAAAAAAAZg/1lCSdLHWcK4/s640/Zuyev+Workers+Club,+Moscow+1926.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">The Zuyev Workers Club. Ilya Golosov, 1926. A precedent of double skin glazed walls in Moscow before the Centrosoyuz.</td></tr>
</tbody></table>
But the opaque wall as it was designed, even without blowed air in the cavity, would have been much better in terms of insulation than the one-layer stone wall finally built, with a thickness of 40cm.<br />
<br /></div>
<div>
</div>
<div>
Could these two concepts, the 'Mur neutralisant' and the 'Respiration exacte' really work? Were they logical? The answer depends on the system. </div>
<div class="MsoNormal" style="margin: 0cm 0cm 0pt;">
<br /></div>
It is not clear to me what Le Corbusier meant by 'Respiration exacte' (I suspect it's not just me; Corbu was not an engineer and he did not describe the concept in depth). The Centrosoyuz drawings show a viable closed circuit distribution, a system which might have worked applying the knowledge in air conditioning already available at the time. Trying to keep the inner temperature at 18º all year round might be onerous in terms of energy consumption, but it was a good intention in terms of comfort. I don't see a real invention here but the application of an existing concept. <br />
<div>
<br /></div>
<div>
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/-Ts0zRlG0cxk/T5BvNZDpL7I/AAAAAAAAAaI/xBHiVZuHwWc/s1600/Centrosoyuz+model.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="268" src="http://1.bp.blogspot.com/-Ts0zRlG0cxk/T5BvNZDpL7I/AAAAAAAAAaI/xBHiVZuHwWc/s400/Centrosoyuz+model.png" width="400" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Model for the Centrosoyuz complex</td></tr>
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In terms of viability the 'Mur neutralisant' is much more difficult to accept; not because it was ahead of its time but simply because it was not reasonable. The concept of a neutralising wall was tested and calculated by two independent companies at the time, one French and the other American. Both Saint Gobain after their twin-box test and the American Blower Company in their calculations concluded that such a system would require an enormous amount of energy to really make a difference on the inner temperature. And I agree without conducting any tests or calculations, because of two weaknesses: too large conductivity (heat in the cavity would scape out in winter) and no control of radiant heat (solar radiation would come in during summer). Let us see this in a bit more detail.<br />
<br /></div>
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right; margin-left: 1em; text-align: right;"><tbody>
<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/-HCNOSuhyebs/T5Bvp5T1DfI/AAAAAAAAAaQ/16MLmLM78sI/s1600/Centrosoyuz+street+1.png" imageanchor="1" style="clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="409" src="http://3.bp.blogspot.com/-HCNOSuhyebs/T5Bvp5T1DfI/AAAAAAAAAaQ/16MLmLM78sI/s640/Centrosoyuz+street+1.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">The Centrosoyuz after its opening. The main glazed walls are double glass walls but with no intermediate heating system.</td></tr>
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First the conductivity issue: the air-filled cavity would quickly try to equalise its temperature with the outer one - because the temperature gap would usually be higher to the outside than to the inside of the room. A single glass pane has a very high thermal conductivity, meaning that the heat would flow out (in winter) and into the cavity (in summer) instead of warming or cooling (respectively) the air in the room adjacent to the inner side of the glass. The guys from Saint Gobain, who were surely aware of the patents in double glazing already taking place in America, suggested a better alternative: a double glazing on the outside layer instead of a simple glass. And today we would suggest an even better alternative: a triple glass with low emisivity coatings and argon-filled cavities without any active mechanism inside.<br />
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<div>
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/-JDSQ7F2hHLg/T5BwJsrGAjI/AAAAAAAAAaY/gvwcwVtUTY0/s1600/Centrosoyuz+street+2.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="340" src="http://2.bp.blogspot.com/-JDSQ7F2hHLg/T5BwJsrGAjI/AAAAAAAAAaY/gvwcwVtUTY0/s640/Centrosoyuz+street+2.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Views of Centrosoyuz today</td></tr>
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<br /></div>
<div>
But that would not be enough: we have to take care of the solar radiation, as Le Corbusier would learn the hard way at his Cité de Refuge for the Salvation Army in Paris, based on a project started in 1929 and finished in 1933. The story is well known. This is a text written by Le Corbusier defending his active air-handling principles for La Cité de Refuge in 1931:<br />
<blockquote class="tr_bq">
“Our Invention, to stop the air at 18 degrees undergoing any external influence… These walls are envisaged in glass, stone, or mixed forms, consisting of a double membrane with a space of a few centimeters between them… a space that surrounds the building underneath, up the walls, over the roof terrace… </blockquote>
<blockquote class="tr_bq">
Another thermal plant is installed for heating and cooling, two fans, one blowing, one sucking; another closed circuit… Result, we control things so that the surface of the interior membrane holds 18 degrees”</blockquote>
</div>
<div>
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://4.bp.blogspot.com/-JUlmi1gn_9Q/T5BwcT6t-2I/AAAAAAAAAag/lUxxRWlI-rg/s1600/Cite%CC%81+de+Refuge+before+-+after.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="326" src="http://4.bp.blogspot.com/-JUlmi1gn_9Q/T5BwcT6t-2I/AAAAAAAAAag/lUxxRWlI-rg/s640/Cite%CC%81+de+Refuge+before+-+after.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">The South facade of the Cité de Refuge building right after completion in 1933 and as it is now, with the brise-soleils and the sliding windows.</td></tr>
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<br />
In spite of his great selling capability, Corbu was able to implement only one third of his active principles in the Salvation Army building. The south-facing single glazed facade of 1,000m2 was completely air-tight (no opening windows), but the 'Mur neutralisant' and the 'Respiration exacte' were rejected due to budget constraints. The building remained rather warm during the opening winter, but it proved a complete failure the next summer. Corbu blaimed the absence of air conditioning - true but expensive for a building like this - while the occupants were just asking for opening windows to provide some natural ventilation.<br />
<br />
Both (Corbu and his client) were partly right, although the final solution would only come as a consequence of the bombings in Paris. The facade was completely destroyed during the war and Le Corbusier received the commision for rebuilding it. This time, after his trips to Algeria, Argentina and Brazil he had the final answer to the actual problem: an external sun screen to control solar radiation, or 'brise-soleil' was added outside the glass layer. This concept, a passive measure unlike the other two, would become an integral part of Le Corbu's architecture until the end of his career.<br />
<br /></div>
<div>
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/-aaRP5Heh4Qg/T43jn-8iRII/AAAAAAAAAZo/639QUjn4mmg/s1600/Unite%CC%81+d'Habitation+Marseille+and+brise-soleil+principle.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="320" src="http://3.bp.blogspot.com/-aaRP5Heh4Qg/T43jn-8iRII/AAAAAAAAAZo/639QUjn4mmg/s640/Unite%CC%81+d'Habitation+Marseille+and+brise-soleil+principle.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">The brise-soleil at its most after the War: the Unité d'Habitation in Marseille and sketches by LC on sun control.</td></tr>
</tbody></table>
<br /></div>
How did these trials and errors influence Corbu's vision on architecture? In my opinion the failure of his two active systems, 'Mur neutralisant' and 'Respiration exacte' in Paris and in Moscow led him towards embracing passive control systems after 1935. His architecture becomes more massive, concrete walls take precedence over naked glass and the brise-soleil reigns over every opening. His assistants during the fifties - as Iannis Xenakis in Chandigarh - are better informed about climate control for human comfort. Texts as Victor Olgyay's 'Design with Climate' (1963) emerge partly as a reaction to the excesses of the International Style, but also partly in line with Le Corbusier's view of an architecture more in contact with earth and natural environment.<br />
<br />
Bioclimatism, solar charts, wind blow control, ventilation, illumination, healthy spaces... all these terms define Le Corbusier's architectural production after the war until the end of his prolific career. Corbu's strong alignment with these concepts was clearly an invitation for younger generations of architects to act with diffidence in regards to mechanization of internal climate. <br />
<div>
</div>
<div>
Le Corbusier's early intuition about a glazed 'Mur neutralisant' as a way to achieve a 'Respiration exacte' inside his buildings was not right. But he seemed to have learned the lesson, moved on and helped young architects to learn it as well. Others cannot say the same.<br />
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<div>
</div>
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/-SdOy-i1HM9Q/T41jJQMoekI/AAAAAAAAAZI/ZKPCJGs11FE/s1600/Corbu+in+Moscow+1932.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="472" nda="true" src="http://2.bp.blogspot.com/-SdOy-i1HM9Q/T41jJQMoekI/AAAAAAAAAZI/ZKPCJGs11FE/s640/Corbu+in+Moscow+1932.jpg" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><div class="wp-caption-text">
Le Corbusier sitting in front of the site for the Centrosoyuz Building in Moscow (March 1931)</div>
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Let me finish this post with a small present for Corbu-addicts. These are a few lines of a long letter written by Le Corbusier in 1932 (at the time of construction of the Centrosoyuz, which he calls the Palace) to the Soviet Commissar of Enlightenment Anatolii Lunacharskii. The translation has been provided by Ross Wolfe, and the whole text of the letter can be found <a href="http://rosswolfe.wordpress.com/2011/06/28/a-hitherto-untranslated-letter-from-le-corbusier-to-anatolii-lunacharskii/" target="_blank">here</a>. Corbu was asking this soviet politician for permission to organize a conference to present his architectural principles. And he was clever enough to sound 'scientific' and progressive in order to get a positive answer... <br />
<div>
<blockquote class="tr_bq">
<div style="text-align: justify;">
"In Moscow, I could — outside the Palace — publicly speak of the <em>Radiant City</em>, and explain where progress and the grand view have led us and shown to your country, which is the only one possessing the institutions that permit the realization of modernist programs. The technical detail of the questions concerning:</div>
<div style="padding-left: 30px; text-align: justify;">
architectural reform</div>
<div style="padding-left: 30px; text-align: justify;">
the 24-hour <em>solar day</em> and its programme</div>
<div style="padding-left: 30px; text-align: justify;">
the new techniques of <em>exact respiration</em> inside buildings (with the recent laboratory experiments at St.-Gobain) (the most pressing problem facing the USSR)</div>
<div style="padding-left: 30px; text-align: justify;">
the problems which agriculture poses for the domestic economy</div>
<div style="padding-left: 30px; text-align: justify;">
the soundproofing of homes</div>
<div style="padding-left: 30px; text-align: justify;">
acoustics</div>
<div style="text-align: justify;">
Here are the truths, realities, the long-range items that are informed by the spirit of the five-year Plan — much more than certain restrictive methods, Malthusian and lacking imagination, which have been so warmly embraced in the USSR.</div>
<div style="text-align: justify;">
And if anyone wants, I could speak <em>of</em> <em>proportion</em>, of beauty, those things that are the driving forces of my life, because happiness is not possible without a sense of quality."</div>
</blockquote>
<div>
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/-iuDB90GRTos/T5OwP1WIrRI/AAAAAAAAAa4/MQ4RbNJWAnE/s1600/The+solar+cycle,+LC+1954.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="400" src="http://3.bp.blogspot.com/-iuDB90GRTos/T5OwP1WIrRI/AAAAAAAAAa4/MQ4RbNJWAnE/s400/The+solar+cycle,+LC+1954.png" width="336" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">The solar cycle, LC 1954</td></tr>
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It has taken me days to understand the meaning of 'the 24-hour solar day and its programmme' but it is the clue to this story. What Corbu meant by the 24-hour solar day is wonderfully depicted - and described - in the attached later sketch from 1954. Nothing to do with the 'Mur neutralisant', all the opposite.<br />
<br />
What this letter tells us is that Le Corbusier was at the time of writing, as early as in 1932, already departing from the mechanistic world of the 'thermal machine' and opting for the order of solar profit, of solar control. A world where bureaucrats or budget constraints would not oppose his inventions any longer. A world where energy would come free and abundant, only requiring control, not production.</div>
<div>
<br />
But his interest remained the same all around this mental process: the search of happiness through architecture. Because, as his final words resonate like a manifesto:<br />
<br />
"happiness is not possible without a sense of quality..."</div>
</div>Ignacio Fernández Sollahttp://www.blogger.com/profile/03918193520738485621noreply@blogger.com21tag:blogger.com,1999:blog-1298203288964657974.post-26861831488645730422011-12-28T00:04:00.002+01:002011-12-28T08:08:13.949+01:00External timber cladding: the book<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/-OTbm1X3vyMI/TvpMiQnCF_I/AAAAAAAAAYI/PRxsuG4pNEY/s1600/External+Timber+Cladding+front+page.jpg" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="640" src="http://3.bp.blogspot.com/-OTbm1X3vyMI/TvpMiQnCF_I/AAAAAAAAAYI/PRxsuG4pNEY/s640/External+Timber+Cladding+front+page.jpg" width="449" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Langley Academy, Slough. Foster + Partners. Western red cedar</td></tr>
</tbody></table>Timber facades have long been used on low-rise housing in North America and in Scandinavia. Most recently timber cladding is becoming popular in some other countries, Austria and the UK among them. Moreover, timber is nowadays being used as an external finish on medium-rise and non-domestic buildings.<br />
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But it is not easy. The main uncertainties related with using timber in facades involve: durability, weathering, dimensional change, corrosion, wind resistance and fire safety. Now, considering this long list, does it mean that timber is unsuitable as an external finish? Far from it. If design intent and construction details are in tune with its characteristics, timber can be a versatile facade material with a unique combination of performance benefits.<br />
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Architects in search of guidelines on how to use timber in facades have reasons to congratulate. This post is devoted to a recent book (released in April 2011) whose title says it all: '<a href="https://www.facebook.com/pages/External-Timber-Cladding/197817126914662" target="_blank">External timber cladding: Design, Installation and Performance</a>'. Its authors are Ivor Davies, a researcher from Edinburgh Napier University, and John Wood, professor of engineering at the same Scottish university. The book is more than its authors' baby. It is one of the outputs of a trans-national, EU financed project titled <i>'External timber cladding in exposed maritime conditions'</i>. The project had inputs from Scotland, Iceland and Norway. More info about the project can be found <a href="http://www.scotland.gov.uk/Publications/2002/03/15098/8731" target="_blank">here</a>.<br />
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<div class="separator" style="clear: both; text-align: center;"><a href="http://3.bp.blogspot.com/-oiKHvJjMy9Y/TvpMxslUJxI/AAAAAAAAAYU/iVmoHkFD-iY/s1600/Suttie+Centre+for+Teaching%252C+University+of+Aberdeen+2009.jpg" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="576" src="http://3.bp.blogspot.com/-oiKHvJjMy9Y/TvpMxslUJxI/AAAAAAAAAYU/iVmoHkFD-iY/s640/Suttie+Centre+for+Teaching%252C+University+of+Aberdeen+2009.jpg" width="640" /></a></div>But this book is much more than the summary of an international study, and it is worth down to the last page if you are interested in timber for facades. In fact, it can be considered as the first true guidelines for timber facade engineering. The authors note very rightly that, during the past decade, facade engineers have tended to ignore timber in favour of more conventional - or more <i>à la mode</i> - materials like concrete, steel and glass. Timber exteriors have been left to architects (general practitioners) and timber specialist suppliers. This has proven risky sometimes, and reductive in most cases. Even more, the main technical standard for facades in the UK (the standard from CWCT) largerly ignores timber, whilst the existing guidance on timber cladding only covers a limited range of topics. This book comes to fill the gap between timber facade construction and facade engineering. It was about time!<br />
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The book is structured in six parts, each one dealing with the answer to six fundamental questions, exposed in a sort of 'ignorance pyramid':<br />
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<div style="text-align: center;"><b>What is wood?</b></div><div style="text-align: center;"><b>How wet does it get?</b></div><div style="text-align: center;"><b>What effects does it have?</b></div><div style="text-align: center;"><b>How are these effects controlled?</b></div><div style="text-align: center;"><b>How do the controls relate to fire safety?</b></div><div style="text-align: center;"><b>What does all of this mean for facade engineering?</b></div><br />
Chapter 1 describes what performance-based design means for timber facades, with a fundamental section on service life. Chapert 2, the top of the pyramid, deals with timber as a facade material, describing its main parameters. Chapter 3 covers moisture conditions in timber facades, and how to predict and to prevent them.<br />
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<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/-NV1QAoXSJns/TvpM7W_n72I/AAAAAAAAAYg/qNpmRIYEu7A/s1600/Western+red+cedar+facade+with+pronounced+staining.jpg" imageanchor="1" style="clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="301" src="http://2.bp.blogspot.com/-NV1QAoXSJns/TvpM7W_n72I/AAAAAAAAAYg/qNpmRIYEu7A/s400/Western+red+cedar+facade+with+pronounced+staining.jpg" width="400" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Western red cedar facade with pronounced staining</td></tr>
</tbody></table>Chapter 4, as an outcome of the trans-national study, presents the results of site tests conducted on Sitka spruce as a timber cladding. Chapter 5 continues down the pyramid with fungal decay and insect attack. Chapter 6 goes for weathering, and how can we anticipate or respond to weathering in exposed timber cladding. In this chapter we understand why virtually all timber facades in Scandinavia are given an opaque surface coating - good to remember.<br />
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Chapter 7 adds to our limited knowledge in dimensional change on wood, and on how / why timber shrinks and moves. Good news for us: movements can be limited and estimated. Chapter 8 goes for corrosion - yes, that of metal fastenings, flashings and brackets embedded in timber. Chapter 9 describes in more depth the structural performance of timber facades - not of structures - which is an often ignored issue. Windloads, robustness of connections, dowel type fasteners and strenght grading are discussed here.<br />
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<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/-0BBc-xki0-o/TvpNIruuRLI/AAAAAAAAAYs/rfnCYzt3h4g/s1600/Selection+process+of+timber+design.jpg" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="640" src="http://3.bp.blogspot.com/-0BBc-xki0-o/TvpNIruuRLI/AAAAAAAAAYs/rfnCYzt3h4g/s640/Selection+process+of+timber+design.jpg" width="387" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Selection process of timber design</td></tr>
</tbody></table>Chapter 10 contains some of the most innovative pages: design for durability. It starts with a decision sequence to aid selection of a timber cladding design from a durability point of view - a must. It then goes down the sequence using the relevant EN standards on timber durability and preservation. It finally relates service life with timber class and use / exposure. Interestingly the authors don't take a side in the discussion pro / against wood preservatives: they present us the arguments in favour and against, so that we can decide case by case - as it should be.<br />
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Chapters 11 to 15 deal with fire and timber buildings. The fire triangle, fire testing, fire performance of timber, how to limit external fire spread, the role of air cavities, and a summary of fire regulations in the UK. Finally, a long chapter 16 is devoted to construction details for timber facades. This is an issue largerly discussed in other manuals, but again the authors bring novelty to the case, aided by clear and well drawn details. One of the good points is the treatment given to the junction between heavy (brick) and lightweight (timber) cladding.<br />
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The book ends with an updated and interesting list of appendices and references, among them the British and European standards on timber for panelling and external cladding.<br />
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<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/-pJ6Jygs30YI/TvpNXgfABRI/AAAAAAAAAY4/MzJYuAfqGyw/s1600/Horizontal+timber+cladding+details.jpg" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" src="http://2.bp.blogspot.com/-pJ6Jygs30YI/TvpNXgfABRI/AAAAAAAAAY4/MzJYuAfqGyw/s1600/Horizontal+timber+cladding+details.jpg" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Horizontal timber cladding details</td></tr>
</tbody></table>In summary: if you are tired of simple and often repeated statements about how timber facades work, and want to know what is really going on and how this should inform your design decisions, this is your book. The authors challenge some of the prevailing assumtions about moisture, its effects and how they are best controlled. New light is shed on how moisture issues affect, and are affected by, the need to ensure that fire safety is fully addressed. And the construction details are based on a combination of new experimental data and a fresh appraisal and synthesis of existing information - they deserve a look and some thought, not just a copy-paste!<br />
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Go and buy it. You'll find the link to the publisher at the title of this post. It's not cheap, but it's worth every penny.Ignacio Fernández Sollahttp://www.blogger.com/profile/03918193520738485621noreply@blogger.com22tag:blogger.com,1999:blog-1298203288964657974.post-18775196623018771222011-12-17T13:13:00.048+01:002019-09-12T09:11:03.385+02:00Cupples Products: a Tall Tale of American curtain wallingHistory is unfair with master builders. Do you know the relationship between these four behemoths of the 20th century architecture: the John Hancock Center in Chicago, the Twin Towers in NYC, the Sears Tower in Chicago and the Hong Kong & Shanghai Bank headquarters in Honk Kong? The relationship is their skin. The curtain walls and external cladding elements of these four buidings were designed and fabricated in the same place: a factory in the plains near Saint Louis, Missouri. <br />
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<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/-ZmfLuxfgzS8/Tuxu9VnAMLI/AAAAAAAAAXo/DjdZmZYHsyY/s1600/Pei+1.png" imageanchor="1" style="clear: left; cssfloat: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="400" oda="true" src="https://1.bp.blogspot.com/-ZmfLuxfgzS8/Tuxu9VnAMLI/AAAAAAAAAXo/DjdZmZYHsyY/s400/Pei+1.png" width="281" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Webb and Knapp Tower in 34th Street, NYC. I.M. Pei</td></tr>
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That place had a name that was equivalent to glazed facades during the great decades of the sixties and seventies: Cupples Products Inc. To whom does that name recall anything? Well, ask Norman Foster or I.M. Pei (or Gordon Bunshaft from SOM or even Mies himself if they were alive). Of course, they would answer: Cupples was my curtain wall contractor of choice back then.<br />
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That was back then. Today, if you search Cupples in Google you get files from old legal actions and their last address, a suite in Saint Louis. The nearest website is a link to Enclos, the curtain wall company that lastly absorbed Cupples know-how in curtain walling at the turn of the millenium.<br />
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There is something to learn from this company, parallel to the growth of US cities in the second half of the 20th century. Cupples was one of the very early entrants into the new industry of curtain walling right after the war ended. Started in 1946 as a manufacturer of residential of window products, the company rapidly progressed into the design development, engineering, fabrication, assembly and field installation of custom curtain wall systems. Cupples became a provider of glazed solutions to architects and builders eager for new facade technology. One of their first client architects was I.M. Pei, for whom they delivered the curtain wall of Webb & Knapp Tower in 34th Street, NYC. This building was built in 1954 for the headquarters of Webb & Knapp , a local tycoon similar to Donald Trump, for whom young Pei worked as an architect during his early career. Pei would remain linked to Cupples as we will see. <br />
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<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/-RU6ZCl76cMw/TupqcrgaJNI/AAAAAAAAAWQ/TVXNMumQgJk/s1600/Cadet+chapel.png" imageanchor="1" style="clear: left; cssfloat: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="408" oda="true" src="https://1.bp.blogspot.com/-RU6ZCl76cMw/TupqcrgaJNI/AAAAAAAAAWQ/TVXNMumQgJk/s640/Cadet+chapel.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">U.S. Air Force Academy, Colorado. Cadets Chapel. Skidmore Owings and Merrill, 1959-1963</td></tr>
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At the end of the fifties Cupples start working for Skidmore Owings & Merrill, another architect - contractor collaboration that would last long. The U.S. Air Force Academy in Colorado (with its characteristic Cadet Chapel pictured above, finished in 1963) is the most prominent of these early works. It is interesting to note that the chapel has just been refurbished, fifty years after completion. See the <a href="http://som.com/content.cfm/united_states_air_force_academy_cadet_chapel">SOM webpage for details</a>. </div>
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In the fifties and sixties curtain walling was an integrated business. In a way not rivalled by the biggest Chinese suppliers today, Cupples factory included under one roof these production lines: aluminium extrusion, anodizing and liquid coating, cutting, punching, drilling, curving, bending, mechanizing and assembly of curtain wall units. Their designers were able to study and solve the intricacies of a very complex facade; while at the same time they would deliver off-the-shelf simple systems as Horizon, a stick curtain wall very popular up to the nineties. </div>
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<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/-vrAgMKnOtKU/TuprtzV1SMI/AAAAAAAAAWY/hhhXBKGuDOs/s1600/Lake+Point+Towers.jpg" imageanchor="1" style="clear: left; cssfloat: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="640" oda="true" src="https://2.bp.blogspot.com/-vrAgMKnOtKU/TuprtzV1SMI/AAAAAAAAAWY/hhhXBKGuDOs/s640/Lake+Point+Towers.jpg" width="370" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Lake Point Towers, Chicago</td></tr>
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In 1960 Alcoa, the aluminium giant, buys Cupples and the great story begins for the guys in Saint Louis. The sixties was the era of the sheer towers. New York adopted a zoning resolution encouraging architects to set off their buildings and to enrich land use. The new towers were pulled in from the building line to form landscaped plazas and obtain the maximum permissible sheer height. Soaring from open plazas, aluminium and glass enclosed buildings dominated the US cities. Curtain walling technology also experienced a jump forward: more sophisticated engineering and manufacturing techniques were developed, as pressure equalization and laser technology. Cupples introduced and became a leader in color anodizing. <br />
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The sixties were the golden years for Cupples. The list of buildings whose facades were clad by Cupples this decade is simply extraordinary.<br />
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The image above, the <a href="http://www.lakepointtower.org/sub_category_list.asp?category=31&title=Architecture+of+Lake+Point+Tower">Lake Point Tower Apartments</a>, is a project of Schipporeit & Heinrich in Chicago finished in 1968. The link to Mies Van der Rohe is obvious, although this is not a Mies's work. Please have a look at this <a href="http://www.youtube.com/watch?feature=endscreen&v=q10NnA6UGXk&NR=1">video from 1969</a> - the third part of three explaining how the tower was built - here dedicated to curtain walling. A real piece of art for us conoisseurs. Cupples worked for Mies in at least two projects: the Pavillion - Colonnade apartments in Newark and the One Charles Center in Baltimore. Two minor projects for the German master but equally interesting.<br />
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Another project from the sixties, the <a href="http://en.wikipedia.org/wiki/John_Hancock_Tower">John Hancock Tower in Boston</a>, with I.M. Pei & H.N. Cobb (below left). It was actually completed in 1971, but was not opened until 1976. This is the famous (or better infamous) 'plywood building', so nicknamed because of the glass failures it suffered right before completion. This is still the perfect case study for climatic loads acting on insulated glass and how to avoid them - by reducing the stiffness of the bonding between the inner and outer panes of glass. But this is another story. <br />
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In San Francisco we find a good example of the decade: the <a href="http://www.aviewoncities.com/buildings/sf/44montgomerystreet.htm">Wells & Fargo Tower</a>, finished in 1966 by John Graham (one of the corporate architects in those days). A very elegant and slender tower, better than most of the SOM buildings in the decade. I am not sure if the vertical shiny cladding is stainless steel or anodized aluminium, but in any case it reflects prosperity and optimism (see picture below right).<br />
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<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/-Zo7EFt7X3Bw/TupxeoudVEI/AAAAAAAAAWo/RYtHd31gJN8/s1600/Boston+and+SF.png" imageanchor="1" style="clear: left; cssfloat: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="432" oda="true" src="https://2.bp.blogspot.com/-Zo7EFt7X3Bw/TupxeoudVEI/AAAAAAAAAWo/RYtHd31gJN8/s640/Boston+and+SF.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Left, John Hancock Building in Boston, I.M. Pei. Right, Wells & Fargo Bank in San Francisco, John Graham.</td></tr>
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Back to Chicago and we find one of the real giants: the 100-storey <a href="http://som.com/content.cfm/john_hancock_center">John Hancock Center</a>, with Bruce Graham and Fazlur Khan (both from SOM) as main architect and main engineer respectively. Completed in 1969, its curtain wall took 2.5 million pounds (1,100 tons) of aluminium and brackets and 300,000 sqf (28,000 m2) of glass.<br />
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<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/-XheoNITPeQY/Tupwoi_kZOI/AAAAAAAAAWg/WlAyXz5V_1w/s1600/John+Hancock+Chicago.png" imageanchor="1" style="clear: left; cssfloat: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="384" oda="true" src="https://1.bp.blogspot.com/-XheoNITPeQY/Tupwoi_kZOI/AAAAAAAAAWg/WlAyXz5V_1w/s640/John+Hancock+Chicago.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">The John Hancock Center in Chicago by Bruce Graham and Fazlur Khan from SOM, finished in 1969.</td></tr>
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During the installation of the John Hancock Center in Chicago, in November 1967, Cupples changed hands for the second time: Alcoa sold it to the metal company H.H. Robertson, and Cupples became Cupples Products Division within Robertson. The new boss was a giant of metal cladding and steel elements for slabs and ceilings, and would soon begin to be well known by their sandwich panels, branded as Formawall. Cupples had a unique position as the only aluminium and glass supplier in the conglomerate, thus allowing Robertson to provide one-stop-shop services for structure and cladding all around the world. Cupples employed 850 persons and was present in curtain walling, aluminium doors, window frames, store fronts, entrances and suspended ceilings at the time of Robertson's take over.</div>
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Between the sixties and the seventies, and both in Chicago, these are the two other big buildings clad by Cupples there: the Standard Oil Building and the Sears Tower. The <a href="http://en.wikipedia.org/wiki/Aon_Center_(Chicago)">Standard Oil Building</a>, finished in 1972-73, has another interesting story of failure due to the Carrara marble cladding used (not by Cupples) which failed due to bending - a process known as thermal hysteresis. The solution was hard: to remove the whole marble cladding and to replace it with light coloured and thicker granite panels at an incredible cost. </div>
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<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/-0ByP83FFb90/Tup2uTTHYPI/AAAAAAAAAWw/-ZXRtxwsXBA/s1600/Standard+Oil+and+Sears+Towers.png" imageanchor="1" style="clear: left; cssfloat: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="568" oda="true" src="https://3.bp.blogspot.com/-0ByP83FFb90/Tup2uTTHYPI/AAAAAAAAAWw/-ZXRtxwsXBA/s640/Standard+Oil+and+Sears+Towers.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Left, the Standard Oil Building in Chicago by Perkins & Will with Edward Durrell Stone (Image credit: <a href="https://secure-web.cisco.com/1QoXa0dWAeB9HkBe9WFuRIEz4XKWWAsSf3IdQzBy5wXyx0SRju1zHG_v9DweWXmtby1MT1krwtJ-2H7LECpxndTeX7QqICoQIB7mzV-wLmvZ4MMnEBEVb9E1UjZuZ0Wulfgb0V3RHbBkHSgdI6M-qO3pdN0buLgR0wuczaNxdRUtc1psML5I3cAQG4jKyWPI4MmsvadqdHuLrZOP7kMH_p8s6imDx7CCI2f2WfGYv2AA6xW0ZLR38RBG1DJcmHT1_DOJTQzqiys-BKZrkdDgYVUnWJ3ge6z0XwOuCpSTeIlUFeDQB3RGEWuSzsPDi-RIAx_26ylst--tBjuNxmCxDlA/https%3A%2F%2Fcommons.wikimedia.org%2Fwiki%2FFile%3A2004-07-14_1880x2820_chicago_aon_looking_up.jpg" target="_blank">J. Crocker</a>). Right, the Sears Tower by SOM.</td></tr>
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The <a href="http://som.com/content.cfm/sears_tower">Sears Tower</a>, once again by SOM and finished in 1973, will deserve a future post only for itself, so no more comments by now. <br />
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We are now well into the seventies. The construction of the World Trade Center in lower Manhattan is going on and Cupples people are busy with fabrication and erection of the two towers, which by the time would be the tallest in the world. Minoru Yamasaki and Associates with Emery Roth & Sons were the architects. Skilling, Helle, Christiansen and Leslie Robertson were the engineers. Tishman was the general contractor. <br />
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<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/-JdIU3UORROk/TuxNIHm2YwI/AAAAAAAAAW4/MfQWMXl2CmQ/s1600/WTC+2.png" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="288" oda="true" src="https://2.bp.blogspot.com/-JdIU3UORROk/TuxNIHm2YwI/AAAAAAAAAW4/MfQWMXl2CmQ/s640/WTC+2.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">World Trade Center towers in lower Manhattan, 1973. Minoru Yamasaki and Leslie Robertson.</td></tr>
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Many new design, engineering and construction techniques were required for the structures. The exterior skin was 2-million sqf (185,000 m2) of Cupples aluminium curtain wall. It used a then unique and progressive 'pressure equalizing' design which caused wind loads and pressures to be exterted directly upon the building structure rather than the aluminium skin. The steel frame work forming the exterior wall was installed by hoisting in place 3-module opaque prefabricated units, up to 36 ft high and 10 ft wide (11m high x 1m wide). Horizontal aluminium spandrel units - finished with Alcoa Duranodic bronze - were then spliced onto the adjacent unit. All aluminium profiles and sheets were supplied by Alcoa. <br />
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The two buildings included more than 44,000 glass vision units, recessed 10 inches in relation to the external column cladding, achieving some degree of protection from direct sunlight. Another very interesting feature was the anchoring system of the curtain wall to the bottom side of the floor slab. A viscoelastic interlayer between the bracket and the main structure allowed for wind gusts to be transferred but it absorbed part of the dynamic vibration of wind action. It remains to be studied what role - if any - did this viscoelastic shock-absorber have at the time of the planes crash in 2001...<br />
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<tr><td style="text-align: center;"><a href="http://4.bp.blogspot.com/-DbLA-Mf4-jA/TuxNdeX7z5I/AAAAAAAAAXA/ncXmLWcKRis/s1600/WTC+3.jpg" imageanchor="1" style="clear: left; cssfloat: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="428" oda="true" src="https://4.bp.blogspot.com/-DbLA-Mf4-jA/TuxNdeX7z5I/AAAAAAAAAXA/ncXmLWcKRis/s640/WTC+3.jpg" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">WTC towers during construction. The yellow band between the curtain wall and the steel structure was the area of structure undergoing sprayed fireproofing.</td></tr>
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Cupples completed some more interesting projects in the US during the seventies and the eighties. Among them it is worth mentioning two projects of Johnson & Burgee which exemplify the new style of architecture swifting to volumes out of the box or to pure postmodernism. The Garden Grove Community Church in California (aka the Crystal Cathedral) was finished by Cupples in the late seventies. <br />
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<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/-z9REGuQtxZ8/TuxRLT1IUWI/AAAAAAAAAXI/WufwSHd3vDU/s1600/Garden+Grove.jpg" imageanchor="1" style="clear: left; cssfloat: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="428" oda="true" src="https://2.bp.blogspot.com/-z9REGuQtxZ8/TuxRLT1IUWI/AAAAAAAAAXI/WufwSHd3vDU/s640/Garden+Grove.jpg" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Garden Grove community centre (also known as the Crystal Cathedral) by Johnson and Burgee</td></tr>
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The Republic Bank Center in Houston, clad with units of pink granite and glass, is a perfect example of the eighties reaction to sheer transparency, which was not bound to last. Another interesting example of big space container made by Cupples is the State of Illinois Center in Chicago, by Murphy and Jahn.<br />
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<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/-mV_j-8KRUcU/TuxS-5lRAnI/AAAAAAAAAXQ/bbUWrgKGXG0/s1600/Houston+and+Chicago+80%2527s.png" imageanchor="1" style="clear: left; cssfloat: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="376" oda="true" src="https://2.bp.blogspot.com/-mV_j-8KRUcU/TuxS-5lRAnI/AAAAAAAAAXQ/bbUWrgKGXG0/s640/Houston+and+Chicago+80%2527s.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Left: Republic Bank Center in Houston, Johnson & Burgee. Right: State of Illinois Center in Chicago, Murphy and Jahn. </td></tr>
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<tr><td style="text-align: center;"><a href="http://4.bp.blogspot.com/-VoBu3e8auCM/TvofrEOptYI/AAAAAAAAAX8/qP1xsEmdewQ/s1600/Republic+Banc+stone+details.jpg" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="520" src="https://4.bp.blogspot.com/-VoBu3e8auCM/TvofrEOptYI/AAAAAAAAAX8/qP1xsEmdewQ/s640/Republic+Banc+stone+details.jpg" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Republic Bank Center, stone curtain wall horizontal details. Above section @ vision glass, below section @ spandrel</td></tr>
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The next - and probably the last - of the great buildings ever to be covered in glass and aluminium by Cupples was not in the US but abroad: the Hong Kong and Shanghai Banking Corporation headquarters in Hong Kong by Norman Foster, finished in 1985. This is a very successful and rare case of project management led by the architect. Foster proposed the Bank to arrange a team of specialists - architects, engineers and contractors - under a sort of design & build contract where architects were the leading partners both during design and construction.<br />
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<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/-jNyu8II1YLo/TuxWqKI2bEI/AAAAAAAAAXY/CBF_46W9g88/s1600/HSBC+1.png" imageanchor="1" style="clear: left; cssfloat: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="442" oda="true" src="https://2.bp.blogspot.com/-jNyu8II1YLo/TuxWqKI2bEI/AAAAAAAAAXY/CBF_46W9g88/s640/HSBC+1.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">HSBC headquarters in Hong Kong by Foster, 1985: the most expensive corporate building in the world...</td></tr>
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The merit that this scheme could go well can be mainly attributed to Foster's bold vision, but the other players - Arup and Cupples among them - were also critical. It is worth mentioning here the role of Phil Bonzon, the engineer from Cupples that led the design and construction of the facade throughout the whole process. Bonzon's sketches were unanimously praised by Foster team members as the only way for them to understand the intricacies of what they were jointly designing. Again, the cladding of this building deserves a future dedicated post if not a whole PhD thesis...<br />
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<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/-vmKNt9HgmPk/TuxW-2GzVGI/AAAAAAAAAXg/_ahH8BjtDc4/s1600/Phil+Bonzon%2527s+sketches+for+HSBC+facade.png" imageanchor="1" style="clear: left; cssfloat: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="394" oda="true" src="https://1.bp.blogspot.com/-vmKNt9HgmPk/TuxW-2GzVGI/AAAAAAAAAXg/_ahH8BjtDc4/s640/Phil+Bonzon%2527s+sketches+for+HSBC+facade.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Phil Bonzon's sketches for the HSBC facade design. These details prefigure many industry design features by at least ten years</td></tr>
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Nothing can last forever. Cupples lagged behind during the nineties, due not to a specific reason but probably to a number of them. In my opinion the management team did not anticipate that the one-stop-shop model of vertically integrated production was untenable. Cupples people kept for too long a manufacturing structure that was becoming costly and outdated as years passed. The parent company, H.H. Robertson, was also under a similar stress. <br />
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Besides, Cupples was not alone in the market. A later entrant to the curtainwall industry had been operating over the decades under the names of Harmon Contract, Harmon Ltd, and finally Enclos Corp, completing many landmark projects. By the end of the 20th century the two companies, Harmon and Cupples, were operating as sister companies under the same umbrella with Harmon focusing on the domestic US market while Cupples tried to keep pace with international operations. Finally, the two companies became one under the same name, that of Enclos. It can be said that Enclos has inherited and continues Cupples history into the twenty first century.<br />
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<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/-2cJ39n_IjMc/Tu7q4If7WZI/AAAAAAAAAXw/GyIIxYSfupo/s1600/factory+inside.png" imageanchor="1" style="clear: left; cssfloat: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="466" oda="true" src="https://1.bp.blogspot.com/-2cJ39n_IjMc/Tu7q4If7WZI/AAAAAAAAAXw/GyIIxYSfupo/s640/factory+inside.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Internal view of the assembly line during the eighties</td></tr>
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Why am I interested in Cupples? Because of a personal reason. In 1991 I entered the facade business as project manager with Robertson in Spain, dealing with curtain wall projects and working closely with a number of some great American Cupples colleagues, then busy with projects in our country. I learned the first curtain walling lessons from them. People as Rick Hamlin, now in Trainor Glass; or site managers as James Jutson or Tom Watson, a couple of great chaps whith whom being on site was never boring. Those guys taught me the important lessons. That a facade design is not completed util it is installed - design, fabrication and installation being all part of one same process. That many things can go wrong along the process, and one has to be awake and alert to avoid mistakes and correcting them when things happen. That every step should be checked and re-checked before moving to the next one: it saves time, nobody is perfect. That, in summary, a building and its facade is a lineage of decisions made by a bunch of different people, and success is an outcome of everyone, not of the first one in the line. That being humble on site goes along with being better.<br />
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I will never forget those brown helmets with the Cupples name on top. Others will come and build great facades with promising new technologies. But we should never forget those who were so good at opening the trail before us. We owe it to them.</div>
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Ignacio Fernández Sollahttp://www.blogger.com/profile/03918193520738485621noreply@blogger.com56tag:blogger.com,1999:blog-1298203288964657974.post-42818184143876053552011-12-04T18:43:00.003+01:002012-04-26T10:42:22.447+02:00The Louvre pyramids revisitedYes: <i>pyramids</i> in plural. This post will compare the main Louvre pyramid (the one we all remember) with the inverted pyramid, less known but equally noticeable. Both are of course part of I.M. Pei's plan for Le Grand Louvre in Paris, commisioned by President Mitterrand as the first of his 'Grand Ouvres'. But as we will see the similarities between the two end right there. The main pyramid epitomises the end of the <i>structural frame</i> era, while the inverted pyramid represents one of the first examples of our time, the supremacy of <i>structural glass</i>. <br />
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<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/-TvEmCNNX0lA/TpsSE7I4T7I/AAAAAAAAAOw/ZWmfliqUAxw/s1600/main+from+inverted.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="427" src="http://2.bp.blogspot.com/-TvEmCNNX0lA/TpsSE7I4T7I/AAAAAAAAAOw/ZWmfliqUAxw/s640/main+from+inverted.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">An unusual view: the main pyramid seen from the top of the inverted one</td></tr>
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The main pyramid - together with its three small siblings surrounding it - was finished and opened to public in 1989. The inverted pyramid was not completed until 1993. On the earliest sketches made by I.M. Pei back in 1983 the main pyramid, surrounded by the other three and the pools was already there. The inverted pyramid came slightly later in the plan, around 1985, as a standing point marking the entrance from the underground and the parking.<br />
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<tr><td style="text-align: center;"><a href="http://4.bp.blogspot.com/-w3p2Znkt7go/TpsGsjlhYGI/AAAAAAAAAOg/RCojneh0E_w/s1600/Louvre+longitudinal+section.png" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="160" src="http://4.bp.blogspot.com/-w3p2Znkt7go/TpsGsjlhYGI/AAAAAAAAAOg/RCojneh0E_w/s640/Louvre+longitudinal+section.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">The main pyramid (centre) and the inverted pyramid (right). The underground entrance takes place from the right.</td></tr>
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Pei wanted the main pyramid to be the new entrance to the Louvre, so that people had to wait on the Napoleon court to enter the museum. But this proved not enough to manage the thousands of people arriving every day. Soon predominance was given to the underground entrance, be it from the tube line of from the parking lot. Both coincide precisely at the inverted pyramid, so that it now becomes the first glass feature to be discovered by visitors.<br />
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<tr><td style="text-align: center;"><a href="http://4.bp.blogspot.com/-EEg3n-qeNA8/TpsSBUojcsI/AAAAAAAAAOo/MDP_9iNGVOE/s1600/Louvre+plan.png" imageanchor="1" style="clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="218" src="http://4.bp.blogspot.com/-EEg3n-qeNA8/TpsSBUojcsI/AAAAAAAAAOo/MDP_9iNGVOE/s400/Louvre+plan.png" width="400" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">The inverted pyramid between the gardens and the main one</td></tr>
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Why are these two structures so different? Aren't both of them just glass pyramids? Well, not exactly. The first difference is their size. The main pyramid has a square base of 35.4m and a height of 21.6m, while the inverted one has a square base of 15.5m and a height of just 7m. Another reason for the two structures to have been designed different is wind load. The main one has to withstand strong wind loads that don't exist in the case of the inverted pyramid. To be precise, the inverted pyramid top side (which by the way is a very low pyramid in itself) only has suction loads due to wind. But the main reason for these two structures to be remarkably different is a fact of evolution: the engineers who designed the main pyramid remained under the old paradigm of <i>glass as an infill</i>; the engineers that were given responsibility to design the inverted one were pioneers of the new paradigm of <i>glass as a structural element</i>.<br />
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It has taken me a while to find out who the main actors are in this play in two parts. From the architect's side it is clear : I.M. Pei from Pei & Partners (now <a href="http://www.pcf-p.com/">Pei Cobb Freed & Partners</a>) was the design principal. Second in charge was Leonard Jacobson, although the design architect in charge of the pyramids was Yann Weymouth. Yann's sketches between 1983 and 1986 are the visual history of the design process, both in general and in its details.<br />
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<tr><td style="text-align: center;"><a href="http://4.bp.blogspot.com/-rizWxo_J_V0/Tt4BiSmfF8I/AAAAAAAAATk/O0r-wIrFRjU/s1600/I.M.+Pei+and+Jann+Weimouth+at+the+pyramid+site.png" imageanchor="1" style="clear: left; cssfloat: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" dda="true" height="430" src="http://4.bp.blogspot.com/-rizWxo_J_V0/Tt4BiSmfF8I/AAAAAAAAATk/O0r-wIrFRjU/s640/I.M.+Pei+and+Jann+Weimouth+at+the+pyramid+site.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Yann Weimouth and I.M. Pei on site during the main pyramid construction</td></tr>
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<tr><td style="text-align: center;"><a href="http://4.bp.blogspot.com/-GUnWS6kbT9Y/Tpsah9M5ZcI/AAAAAAAAAO4/1DxYO6XY2vo/s1600/countercable+detail.png" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="432" src="http://4.bp.blogspot.com/-GUnWS6kbT9Y/Tpsah9M5ZcI/AAAAAAAAAO4/1DxYO6XY2vo/s640/countercable+detail.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Studies for tension fastening of the main pyramid. The left version was the selected one. Sketch by Yann Weymouth, April 1985.</td></tr>
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Yann, who was fluent in French, lived in Paris between 1984 and 1990. The associate architect (the French local) was Michel Macary. <br />
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<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/-fzDqneEWooc/Tt4D8KJrtuI/AAAAAAAAATs/g39KKV7xBw8/s1600/La+Villette+serres.jpg" imageanchor="1" style="clear: left; cssfloat: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" dda="true" height="400" src="http://1.bp.blogspot.com/-fzDqneEWooc/Tt4D8KJrtuI/AAAAAAAAATs/g39KKV7xBw8/s400/La+Villette+serres.jpg" width="267" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">The 'serres' at La Villette by RFR, 1982-86</td></tr>
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Now comes the conundrum of the story: the engineer's selection. The best engineering firm in glass tensed structures worldwide was at the time very active in Paris: <a href="http://www.rfr-group.com/index.php?id=67&L=0">RFR, Rice Francis Ritchie</a>. This team of one Irish engineer - Peter Rice - and two British architects (Ian Rithchie was 100% architect; Martin Francis was partly a yacht designer) was created in Paris in 1981. RFR had successfully completed the 'serres' at the Parc de la Villette between 1982 and 1986, so they had to be well known to Michel Macary or to Emile Biasini, Mitterrand's man in charge of the whole project. How then RFR were not given the task of engineering the pyramids? The answer - as much as I can guess - must be found in I.M. Pei's contractual conditions: Pei was made 100% responsible of the design without any interference from French officials or local establishment. This included of course the selection of his engineers - which would be <i>his</i> and not a French firm if he wanted to build his Pyramid as pure as he wanted. It is a real pity that Pei was not right in this point - surely without knowing it at the time.<br />
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So the selection for the engineer was made by Pei, and Pei chose the Canadian firm of <a href="http://www.nck.ca/">Nicolet Chartrand Knoll Ltd</a>. What did this firm exactly do at the project? Their role seems to be clear for the large underground concrete structures. Let's not forget that the main pyramid sits atop a 2m-thick concrete slab with large spans. The stair connecting the Napoleon court with the bottom level is also a feat, with its 540º self-supporting curve. As Nicolet Chartrand Knoll refer to the Louvre pyramid in their webpage French version "<i>The scope for the structural engineer, as bluntly expressed by the architect I.M. Pei, was that of <b>building a structure as transparent as technology could reach</b>. Through a close collaboration between the architect, the structural engineer and the other professionals it was possible to reach a successful outcome. Out of about 25 different structures which were studied, one was finally selected </i>". <br />
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Now, letting aside the fact that they studied many options, was the final structure of the main pyramid as transparent as technology could reach by 1986? I humbly disagree, and it seems that Mr Pei was not too impressed by its transparency either. The main point is a conceptual one: this is not the design of a glass pyramid, but the design of a steel pyramid clad with glass. Glass is just filling the space between the stainless steel struts, it is not taking any structural role. As <a href="http://www.mickeekhout.nl/">Mick Eekhout</a> - the Dutch structural glass specialist - would put it, the main pyramid is an example of <i>space frame with integrated glazing</i>. The two details below compare a structure of the mid-80s with the main pyramid detail:<br />
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/-tpNcS03viQU/Tt4FxKOTDTI/AAAAAAAAAT0/zOJ_zuWXx4w/s1600/Comparison+Mero-Louvre+structures.png" imageanchor="1" style="clear: left; cssfloat: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" dda="true" height="466" src="http://1.bp.blogspot.com/-tpNcS03viQU/Tt4FxKOTDTI/AAAAAAAAAT0/zOJ_zuWXx4w/s640/Comparison+Mero-Louvre+structures.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Left: a Mero space frame with integrated framing. Right: the top detail of the main Louvre pyramid </td></tr>
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<a href="http://4.bp.blogspot.com/-RBD53aMpaeM/TptPLv5x-dI/AAAAAAAAAPo/G1llLMn6bhU/s1600/Thibault+Schwartz+02.png" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="315" src="http://4.bp.blogspot.com/-RBD53aMpaeM/TptPLv5x-dI/AAAAAAAAAPo/G1llLMn6bhU/s400/Thibault+Schwartz+02.png" width="400" /></a> The Louvre solution is fairly more <i>integrated</i> than a space frame with a separate glazing as the <a href="http://www.mero-structures.com/">Mero structure</a> with glass on top. The outer mullions have disappeared and now a fairly thin aluminium profile is receiving the glass panels. But the glass is simply sealed at four sides with silicone; it is not making part of the structure at all. Suppose we take out all the rhomboidal glass panels: nothing would happen to the structure, the pyramid would remain in place. The pictures from construction period show this quite clearly. Images below have been taken from the book 'I<a href="http://www.amazon.com/I-M-Pei-Pyramid-Philip-Jodido/dp/3791343416#reader_3791343416">.M. Pei. The Louvre pyramid' by Philip Jodidio</a>, Prestel. It also has great sketches from Yann Weymouth.<br />
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<tr><td style="text-align: center;"><a href="http://4.bp.blogspot.com/-bg8QBy6ufns/Tt4xVZAi9XI/AAAAAAAAAT8/B4mIz-UUvo4/s1600/Glass+installation+on+the+main+pyramid.png" imageanchor="1" style="clear: left; cssfloat: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" dda="true" height="474" src="http://4.bp.blogspot.com/-bg8QBy6ufns/Tt4xVZAi9XI/AAAAAAAAAT8/B4mIz-UUvo4/s640/Glass+installation+on+the+main+pyramid.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Glass being installed at the main pyramid. There was practically no internal scaffolding in this picture. Notice the bespoke cradle to attach the suction cap to the pyramid.</td></tr>
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/-cC_HqYE9iBQ/Tt4z3ni0wQI/AAAAAAAAAUE/rqkfcnpDnTQ/s1600/Scheme+steel+structure+Louvre+pyramid.png" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" dda="true" height="376" src="http://2.bp.blogspot.com/-cC_HqYE9iBQ/Tt4z3ni0wQI/AAAAAAAAAUE/rqkfcnpDnTQ/s640/Scheme+steel+structure+Louvre+pyramid.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Scheme of the steel structure of the main pyramid. Left: steel tubes in rhomboid shape with cables and stiffeners. Right: the same with glass already in place.</td></tr>
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<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/-IDG10SJyICs/Tt409L6BsrI/AAAAAAAAAUM/OqTWspqLEzA/s1600/Louvre+pyramid+during+glazing.png" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" dda="true" height="326" src="http://2.bp.blogspot.com/-IDG10SJyICs/Tt409L6BsrI/AAAAAAAAAUM/OqTWspqLEzA/s640/Louvre+pyramid+during+glazing.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Stages of glass installation on the main pyramid</td></tr>
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If the main Louvre pyramid was an American-Canadian design, how come did RFR start working for this pyramid - and yes, much before the inverted one was started? There are two reasons for that, and probably the two were required. The first reason is to be found in the (French) facade contractor: <a href="http://www.eiffageconstructionmetallique.com/cms/qui-sommes-nous/histoire.html">Eiffel Construction Metallique</a>, precisely the same facade contractor that had undertaken the building of the serres at La Villette some years before. The Eiffel guys entered the design team for the Main Pyramid when it was still in the drawing table - remember: 25 models were studied before concluding on one. They must have seen that the Canadian engineers, expert as they were in concrete structures, found themselves a bit lost with the cables and rods of the pyramid. So Eiffel managed to sub-contract RFR as their experts to discuss design subtleties with the Canadians.<br />
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/-RmIxGwTaYus/Tt42OyGdINI/AAAAAAAAAUU/oLNShuLZj3U/s1600/Louvre+pyramid+node+detail.png" imageanchor="1" style="clear: left; cssfloat: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" dda="true" height="400" src="http://3.bp.blogspot.com/-RmIxGwTaYus/Tt42OyGdINI/AAAAAAAAAUU/oLNShuLZj3U/s400/Louvre+pyramid+node+detail.png" width="308" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Node detail with tubes, bars and cables</td></tr>
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The second reason was Peter Rice. He was at the time part of two companies in parallel: <a href="http://www.arup.com/">Arup</a> - his first employer - and RFR - his new baby. A strong Arup engineering and lighting team, directed by Rice, was working at the same time on the Richelieu wing of the Museum, taking care of the glazing of the three big courts (5,000m2 and 450 tons of steel in total) and of the natural lighting strategies for the whole Richelieu wing. Thus, Rice was already known to and appreciated by the 'proprietaire'. I can imagine Peter Rice inviting Emile Biasini (the boss on site) to take a taxi and visit La Villette sometime during the works.<br />
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Since Rice was engaged with the Arup team, the RFR consulting work for the main pyramid (remember, under the hat of the facade contractor) fell on Martin Francis. Martin was an architect but also a yatch designer. The whole concept of suspended glazing and stainless steel cables owes in fact a lot to the yatching world of mast connections. As part of his sailing activities Martin knew of an American company who were masters in stainless steel rods, cables and riggers for naval architecture. The company name was <a href="http://www.navtec.net/architectural.asp">Navtec</a> and Martin Francis' colleague there was Tim Eliassen. This becomes interesting, and a prove that mixing technologies is always productive. Eliassen, who had studied aeronautical engineering and graduated in nuclear reactors had cofounded Navtec to end up immersed in the world of large sailing yachts, America's cup boats and the like.<br />
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<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/-GLWhmmvBPB4/Tt43x2RcpjI/AAAAAAAAAUk/Ps_C_gwBtvA/s1600/Louvre+pyramid+transparency.png" imageanchor="1" style="clear: left; cssfloat: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" dda="true" height="428" src="http://2.bp.blogspot.com/-GLWhmmvBPB4/Tt43x2RcpjI/AAAAAAAAAUk/Ps_C_gwBtvA/s640/Louvre+pyramid+transparency.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Inner transparency, so much sought after by the architects, depends largerly on the point of view.</td></tr>
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According to <a href="http://www.architectureweek.com/2011/0817/index.html">Mic Patterson</a> (himself a good friend of Tim's and as such a reliable source), in 1987 Elliassen received a call from Francis telling him that there was a project in France that needed his involvement. The main pyramid became the first architectural project for Navtec, where they provided about 3,800 'short pieces of yatch rigging' to Eiffel. After completing the Louvre pyramid Eliassen tried - unsuccessfully - to convince his colleagues of Navtec to enter the business of glass architecture. Navtec comment at the time, according to Patterson, was unforgettable: "roofs leak, you get sued". So Eliassen founded <a href="http://www.tripyramid.com/">TriPyramid Structures</a> - notice the relationship between the name and his first job - in late 1989 and started a long line of high-profile projects, helping US architects to master in the new science of glass and steel. But that's another story.<br />
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://4.bp.blogspot.com/-Kagon4KBM5g/Tt42vzKNazI/AAAAAAAAAUc/FHTZYzlXcvE/s1600/cables+and+rods+main+pyramid.jpg" imageanchor="1" style="clear: left; cssfloat: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" dda="true" height="432" src="http://4.bp.blogspot.com/-Kagon4KBM5g/Tt42vzKNazI/AAAAAAAAAUc/FHTZYzlXcvE/s640/cables+and+rods+main+pyramid.jpg" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">The complexity of connecting elements next to the bottom of the pyramid. Notice the air fans pointing towards the inner face of glass, intended to reduce the risk of condensation.</td></tr>
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A side note about glass selection for the main pyramid will give perspective on how much things have changed since the mid '80s in glass technology. Pei wanted a glass as clear as possible, and he was sure that the required laminated thickness (and even more in diagonal views) would be seen as green form the outside. So under his pressure a new manufacturing process was devised using Fointanebleau white sand -that is, sand very low in iron content - in collaboration with the French firm <a href="http://www.saint-gobain.com/">Saint Gobain</a>. Possible it was, but expensive: the cost of producing a small batch of low-iron glass was huge at the time, and the big boss at Saint Gobain wasn't willing to stop the furnace and introduce such an order. Pei has declared (it's in Jodidio's book) that he went to Mitterrand in person in order to get the glass he wanted. Those were the days: the Emperor stopped the furnaces and glass for the pyramid came out as clear as it had to be...<br />
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<tr><td style="text-align: center;"><a href="http://4.bp.blogspot.com/-tGrOFzJ_t7w/Tt49Ksm-csI/AAAAAAAAAUs/48EqB3GSjhg/s1600/Section+of+the+concrete+slab+below+pyramid.png" imageanchor="1" style="clear: left; cssfloat: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" dda="true" height="406" src="http://4.bp.blogspot.com/-tGrOFzJ_t7w/Tt49Ksm-csI/AAAAAAAAAUs/48EqB3GSjhg/s640/Section+of+the+concrete+slab+below+pyramid.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Section of the concrete slab below the glass pyramid. This was the kingdom of Nicolet Chartrand Knoll, the Canadian engineers who started designing the pyramid concept.</td></tr>
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So the main pyramid ended as best as it could, still not as 'trasparent' as Pei wanted, but it would have a great influence - much larger than the serres of La Villette - in expanding the word of the new structural glass facades to the world.<br />
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Now, Martin Francis had shown Pei how useful it had been to have RFR on board for the main pyramid, and Pei awarded them with the contract for the inverted pyramid. For RFR the next logical step in the linear sequence of the history of glass had to be the disappearance of mullion frames, elevating glass to the primary structural element of the builiding's skin. And this is exactly what happened with the inverted pyramid: the flat, clean glazed surfaces of La Villette lost their ugly steel tube edges and became a pure glass-enclosed volume. The inverted pyramid is to structural glass what the Seagram building was to the history of curtain walling: the culmination of a de-materialization process that had taken years to achieve. And, Pei permitting, the main pyramid with all its glamour would be nothing but the Lever House, located - as its sibling - just some feet away from the real jewell...<br />
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Enough for this post. It's too much text already. Let me finish with some good images and drawings of the inverted pyramid. From the heights of our age it's easy to read and to understand how it works. It surely must have been painful to design, but there it will remail, the light of a candle, forever.<br />
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<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/--t8U4-zs36o/Tt5NH38yYqI/AAAAAAAAAU0/yExVe-6mOV0/s1600/00+Inverted+pyramid+from+inside.jpg" imageanchor="1" style="clear: left; cssfloat: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" dda="true" height="422" src="http://1.bp.blogspot.com/--t8U4-zs36o/Tt5NH38yYqI/AAAAAAAAAU0/yExVe-6mOV0/s640/00+Inverted+pyramid+from+inside.jpg" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Inverted pyramid as seen from the Carousel</td></tr>
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<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/-NBOJ-JNJzQY/Tt5Nbo1F4dI/AAAAAAAAAU8/-7cJiYu01Sg/s1600/01+Inverted+pyramid+structural+diagrams.png" imageanchor="1" style="clear: left; cssfloat: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" dda="true" height="441" src="http://2.bp.blogspot.com/-NBOJ-JNJzQY/Tt5Nbo1F4dI/AAAAAAAAAU8/-7cJiYu01Sg/s640/01+Inverted+pyramid+structural+diagrams.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Inverted pyramid: section and structural diagram</td></tr>
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<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/-Lx3i_hS44qY/Tt5N33CKsFI/AAAAAAAAAVE/KrqaoC3ztNI/s1600/02+Inverted+pyramid+from+below.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" dda="true" height="640" src="http://2.bp.blogspot.com/-Lx3i_hS44qY/Tt5N33CKsFI/AAAAAAAAAVE/KrqaoC3ztNI/s640/02+Inverted+pyramid+from+below.jpg" width="620" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Inverted pyramid from below</td></tr>
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<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/-qHfbiRlkriY/Tt5PuiRy5vI/AAAAAAAAAVM/2ywknKYlwPA/s1600/03+Inverted+pyramid+structural+composition.png" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" dda="true" height="534" src="http://2.bp.blogspot.com/-qHfbiRlkriY/Tt5PuiRy5vI/AAAAAAAAAVM/2ywknKYlwPA/s640/03+Inverted+pyramid+structural+composition.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Inverted pyramid: more structural diagrams</td></tr>
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<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/-UT-bxANZxs4/Tt5P8ekb7tI/AAAAAAAAAVU/1zlty0SqdAM/s1600/05+Inverted+pyramid+and+Pei.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" dda="true" height="426" src="http://1.bp.blogspot.com/-UT-bxANZxs4/Tt5P8ekb7tI/AAAAAAAAAVU/1zlty0SqdAM/s640/05+Inverted+pyramid+and+Pei.jpg" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">I.M. Pei at the bottom of the inverted pyramid</td></tr>
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<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/-dC5bC7V8SGI/Tt5QNwMu9NI/AAAAAAAAAVc/ZaI0Pn9qPaM/s1600/06+Inverted+pyramid+glass+fixing+elements.png" imageanchor="1" style="clear: left; cssfloat: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" dda="true" height="640" src="http://2.bp.blogspot.com/-dC5bC7V8SGI/Tt5QNwMu9NI/AAAAAAAAAVc/ZaI0Pn9qPaM/s640/06+Inverted+pyramid+glass+fixing+elements.png" width="630" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Inverted pyramid: the square brackets support the top square glass units while the cross brackets support the sloped rhomboid glass units. </td></tr>
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<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/-a8YKmZPOtMY/Tt5bdFGTDII/AAAAAAAAAV8/CsfIucEyWTQ/s1600/PA100749.JPG" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="480" src="http://1.bp.blogspot.com/-a8YKmZPOtMY/Tt5bdFGTDII/AAAAAAAAAV8/CsfIucEyWTQ/s640/PA100749.JPG" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Me as Peter Rice, hanging from cables...</td></tr>
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<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/-qjxWAosN3d0/Tt5QvxUL4LI/AAAAAAAAAVk/gcSBt4bJAYE/s1600/07+Inverted+pyramid+glass+fixing+details.png" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" dda="true" height="534" src="http://3.bp.blogspot.com/-qjxWAosN3d0/Tt5QvxUL4LI/AAAAAAAAAVk/gcSBt4bJAYE/s640/07+Inverted+pyramid+glass+fixing+details.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Detail of the top glass brackets. Each glass unit is glued to one side of the bracket at each corner. Slope is 4º for water drainage.</td></tr>
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<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/-JdXV1V6IDUo/Tt5Rg5OcdLI/AAAAAAAAAVs/rdZt5mNKOpY/s1600/08+Inverted+pyramid+glass+fixing+details.png" imageanchor="1" style="clear: left; cssfloat: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" dda="true" height="462" src="http://2.bp.blogspot.com/-JdXV1V6IDUo/Tt5Rg5OcdLI/AAAAAAAAAVs/rdZt5mNKOpY/s640/08+Inverted+pyramid+glass+fixing+details.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Detail of the side glass brackets. Each glass unit is drilled at the corners. The bracket is a mirror piece to avoid swinging and provide additional stiffening.<br />
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</tbody></table>Ignacio Fernández Sollahttp://www.blogger.com/profile/03918193520738485621noreply@blogger.com190tag:blogger.com,1999:blog-1298203288964657974.post-33520821751713478902011-11-27T17:06:00.024+01:002012-03-26T20:33:10.554+02:00The Steiff factory and the birth of curtain wallingThe question of what building in history has <i>the first</i> curtain wall hides a tough academic battle. Here - as almost everywhere - Europeans and Americans diverge. I don't have a strong favourite. What I have is a list of the first curtain walls erected before 1950 that matter to me; and they happen to be located at both sides of the Atlantic.<br />
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Among the Europeans, the Fagus headquarter by Walter Gropius, built in 1911, is celebrating its first 100 years now. Among the Americans, the Halliday building in San Francisco (1917) is a must; same as the Equitable Building in Portland (1946), a forgotten jewell from Pietro Belluschi. Now that I think of it, it would be good to re-visit most of these great oldies in future posts.<br />
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<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/-BlNjsgApGik/TtF22hkmooI/AAAAAAAAAR8/VMbmZYRmsj4/s1600/Steiff+factory+around+1920.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="410" src="http://2.bp.blogspot.com/-BlNjsgApGik/TtF22hkmooI/AAAAAAAAAR8/VMbmZYRmsj4/s640/Steiff+factory+around+1920.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">The east block from 1903 is the front pavilion to the left. The others were built between 1904 and 1908. Picture from the early 1920s.</td></tr>
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<span class="Apple-style-span" style="line-height: 23px;">This post is devoted to one of the first real curtain walls (not a shop front or a wintergarden) ever built, the east block at the <a href="http://www.steiff.de/">Margarete Steiff AG</a> factory in Giengen, erected in 1903. One thing can be said for sure: this was the first double skin facade ever built and - not surprisingly - it had to be located in Germany. Most of the information for this post comes from a paper</span><span class="Apple-style-span" style="line-height: 23px;"> whose title couldn't be more clear: "<a href="http://www.bma.arch.unige.it/PDF/CONSTRUCTION_HISTORY_2009/VOL2/Fissabre-Anke_Niethammer-Bernhard_layouted.pdf" target="_blank">The invention of glazed curtain wall in 1903 - The Steiff toy factory</a>".</span><span class="Apple-style-span" style="line-height: 23px;"> The paper was presented at the 3rd International Congress of Construction History (Cottbus May 2009) and was written by A. Fissabre and B. Niethammer from RWTH Aachen University. More information about the Steiff factory can be found at the <a href="http://rlicc.asro.kuleuven.ac.be/rlicc/docomomo/Registers/2008%20Machine/Germany/5_Giengen_Steiff%20Fabrik.pdf">Docomomo Webpage</a> on the building.</span><br />
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<div style="text-align: left;"><span class="Apple-style-span" style="font-family: inherit; line-height: 23px;">Europe’s most celebrated soft toys, the teddy bears with a button in their ear (‘Knopf im Ohr’) are still manufactured in this all-glazed factory building located in the small town of Giengen, 32 km north-east of Ulm. Margarete Steiff (1847-1909), a native of the town was partially-paralysed at the age of 18 months, but from a dressmaking studio in her father’s house she established a successful company making felt toys. Her nephew Richard Steiff was largely responsible for the company subsequent growth. </span></div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://4.bp.blogspot.com/-w2XCjX7D3K0/TtF3tZqsxbI/AAAAAAAAASE/rdnb3txXQoE/s1600/today+factory+02.jpg" imageanchor="1" style="clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="388" src="http://4.bp.blogspot.com/-w2XCjX7D3K0/TtF3tZqsxbI/AAAAAAAAASE/rdnb3txXQoE/s640/today+factory+02.jpg" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">The original factory building as it is today. Note the diagonal bracings at the large elevation.</td></tr>
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<span class="Apple-style-span" style="line-height: 23px;">Between 1902 and 1903 Richard Steiff took two revolutionary steps: to include bears (sitting bears to be precise) as part of the company toys portfolio and to design a new factory building to cope with the increasing international demand of felt toys.</span><br />
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<span class="Apple-style-span" style="line-height: 23px;">Teddy bears for the American market were in fact the reason behind the construction in 1903 of a new iron and glass building, 30m long, 12m wide and 9.4m high, with an outer shell consisting of a continuous double-glazed wall and a flat roof. The three floors within are supported on iron lattice-work columns. The iron castings and forgings were designed and provided by Eisenwerk Munchen AG, a German contractor. The east building was subsequently extended with two more pavilions between 1904 and 1908, built in timber structure for economic reasons but all with the same double glazed facade.</span><span class="Apple-style-span" style="line-height: 23px;"> </span><br />
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<tr><td style="text-align: center;"><a href="http://4.bp.blogspot.com/-wWpyJkveoMs/TtF4LeADbJI/AAAAAAAAASM/xt3147USpYI/s1600/Steiff+factory+inside.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="458" src="http://4.bp.blogspot.com/-wWpyJkveoMs/TtF4LeADbJI/AAAAAAAAASM/xt3147USpYI/s640/Steiff+factory+inside.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Richard Steiff's intention realised: an all-glazed, well-lit building to increase productivity in toys assembly</td></tr>
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<tr><td style="text-align: center;"><a href="http://4.bp.blogspot.com/-mhf0AujsfyM/TtJkBPVreGI/AAAAAAAAATE/z5KnbUKlbww/s1600/gropius_fagus-factory+interior.jpg" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="238" src="http://4.bp.blogspot.com/-mhf0AujsfyM/TtJkBPVreGI/AAAAAAAAATE/z5KnbUKlbww/s320/gropius_fagus-factory+interior.jpg" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Inner view of the Fagus office wing, Gropius 1911</td></tr>
</tbody></table><span class="Apple-style-span" style="font-family: inherit;"><span class="Apple-style-span" style="line-height: 23px;"></span></span>Look at the image above, and compare it with similar images of the Fagus factory in Alfeld by Gropius, to be built only eight years later. In Alfeld they made shoe trees, here in Geingen they made felt toys. Both activities required natural light. Alfeld is located at the north of Germany, Geingen is at the sunnier south. Natural light inside the Steiff factory is everywhere; if it were not for the clothings and the bulb lamps the image above could be almost contemporary. Look at the curtain drapes at the facade corners: they were there to protect from excessive sun radiation in summer.<br />
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Was Richard Steiff (the company founder's nephew) interested in a brand new industrial aesthetic or was he looking for an engineering ideal? Clearly not at all. He was a toy industrialist himself - he was looking after a continuous workshop plan, well illuminated, where productivity could raise and costs be kept under control. He was also in a hurry: in 1902 the company had received a first order of 3,000 teddy bears from a client in the USA, and subsequent orders were expected. More production space was needed but it had to be efficient, well lit and built quickly.<br />
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<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right; margin-left: 1em; text-align: right;"><tbody>
<tr><td style="text-align: center;"><a href="http://4.bp.blogspot.com/-OZOwbsmZ4gQ/TtJGHdi7uiI/AAAAAAAAASU/WdXlwhW1oZE/s1600/richard_steiff.jpg" imageanchor="1" style="clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="265" src="http://4.bp.blogspot.com/-OZOwbsmZ4gQ/TtJGHdi7uiI/AAAAAAAAASU/WdXlwhW1oZE/s320/richard_steiff.jpg" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Richard Steiff with a teddy bear</td></tr>
</tbody></table>Richard may have taken over some constructive ideas from his father, Friedrich, who was employed in the building sector. According to the paper by Fissabre and Niethammer, Friedrich Steiff might have been influenced by new iron-glass constructions when he visited the Great Exhibition in Chicago in 1893. Upon receiving these ideas from his father, Richard did not only try to realise them but also to improve them. Maximising light was not an easy task as the planning authorities feared workers would go blind in a glass house. But the permission was given and construction could finally start.<br />
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Richard Steiff contracted the Eisenwerk München AG company to design and build the structure of the new factory. It remains unclear who proposed and decided it, but steel was the obvious material for a quick and fire-proof structure. The plans and details of the riveted and wind-braced steel frame were drawn by Eisenwerk München, as shown in the plan drawing shown here below. The three-storey loft, covering an area of 12 x 30m, has a slightly inclined single-pitch roof made of galvanised iron sheet. Inside it is divided in three naves each formed by five bays, punctured by rows of six load-bearing columns each.<br />
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<div style="text-align: left;"></div><table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://4.bp.blogspot.com/-D3j4j3PzlrM/TtJJVqP87fI/AAAAAAAAASc/Y3qJZgPO4HM/s1600/Steiff+factory+plan.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="344" src="http://4.bp.blogspot.com/-D3j4j3PzlrM/TtJJVqP87fI/AAAAAAAAASc/Y3qJZgPO4HM/s640/Steiff+factory+plan.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Second floor plan as shown in the building-permission documentation, 1903. Note the L-shaped ramp for Ms Steiff's wheel-chair extending from bottom left up to top right.</td></tr>
</tbody></table><div style="text-align: center;"></div><div style="font-size: medium; margin: 0px;"><span class="Apple-style-span" style="font-family: inherit;"><span class="Apple-style-span" style="line-height: 23px;"></span></span></div><div style="font-size: medium; margin: 0px;"><span class="Apple-style-span" style="font-family: inherit;"><span class="Apple-style-span" style="line-height: 23px;"></span></span></div><br />
<span class="Apple-style-span" style="font-family: inherit;"><span class="Apple-style-span" style="line-height: 23px;">The main structure of the building (located at the corners) consists of four L-shaped external pillars, riveted on several plates and angle sections. They are linked at the bottom with a lattice truss running around and set in concrete, thus guaranteeing the solid fastening of the frames. The lattice truss is also the basement of nine facade columns of I section set in each of the longitudinal walls, transmitting the perimetral forces onto the ground. The intermediate and short-side facade columns are composed of two U-shaped beams, conntected by small sheet metal streps (see images of the interior above and of the construction below). </span></span><br />
<span class="Apple-style-span" style="font-family: inherit;"><span class="Apple-style-span" style="line-height: 23px;"><br />
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<span class="Apple-style-span" style="font-family: inherit;"><span class="Apple-style-span" style="line-height: 23px;">The load-bearing structure is reinforced by two long diagonal braces on each side of the long facades and cross-butressed ceilings at each floor level. This composition provides three-dimensional stability with a minimum dead load. Prefabrication and dry-fix connections are a fundamental part of the concept, a combination between Marcel Lods and Mero structures but built fifty years before. Even the Maison Dom-ino concept by Le Corbusier would come much later, in 1914-15.</span></span><br />
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<tr><td style="text-align: center;"><a href="http://4.bp.blogspot.com/-FUJmvBiHSr8/TtJMnipSTmI/AAAAAAAAASk/WqztpKke9MM/s1600/Steiff+factory+structure+under+construction.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="456" src="http://4.bp.blogspot.com/-FUJmvBiHSr8/TtJMnipSTmI/AAAAAAAAASk/WqztpKke9MM/s640/Steiff+factory+structure+under+construction.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Construction site in 1903. Note the four corner columns, the nine longitudinal pillars above the lattice truss and the intermediate set of six columns each. The top beams and the diagonal bracing are not instaled yet.</td></tr>
</tbody></table><span class="Apple-style-span" style="font-family: inherit;"><span class="Apple-style-span" style="line-height: 23px;"></span></span>Now it's time to talk about the envelope, the really revolutionary innovation in this small building. The external cover consisted of a double skin façade on all elevations. The inner glazing skin goes from the upper edge of the floor to the lower edge of the ceiling, whereas the outer façade covers the total height of the building. If the inner skin could be understood as a large glass shop-front, not dissimilar to other examples in New York, Chicago or Berlin, the outer skin is nothing but a pure curtain wall. It floats above the facades suspended from the top level; it runs continuously around all three floors, it is attached to the columns to transmit wind loads, and it was conceived as a cavity between two transparent skins to improve its thermal performance whilst allowing natural light.<br />
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<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right; margin-left: 1em; text-align: right;"><tbody>
<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/-sgHHnyDcZR8/TtJUwL_d0tI/AAAAAAAAASs/XEtWogL3iMI/s1600/today+factory+03.jpg" imageanchor="1" style="clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="300" src="http://1.bp.blogspot.com/-sgHHnyDcZR8/TtJUwL_d0tI/AAAAAAAAASs/XEtWogL3iMI/s400/today+factory+03.jpg" width="400" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">The columns are located inside the air cavity</td></tr>
</tbody></table>The facade had been planned from the very beginning as a double-skin construction for heat insulation. The thermal insulation is achieved through an air cavity of around 25cm floating above the envelope. Air exchange is possible by opening box-type windows in every floor, which don't interchange air with the cavity. Additionally, the building was equipped with a low-pressure steam heater - new at the time - that kept the internal temperature stable in winter.<br />
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<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/-eXXi_W5riBw/TtOihElvq0I/AAAAAAAAATU/hna7eXBFBv4/s1600/Steiff+detail+and+elevation+section.png" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" dda="true" height="384" src="http://1.bp.blogspot.com/-eXXi_W5riBw/TtOihElvq0I/AAAAAAAAATU/hna7eXBFBv4/s640/Steiff+detail+and+elevation+section.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Corner detail and section / elevation, taken from <em>Glass Construction Manual</em>, Schittich et al 1999</td></tr>
</tbody></table>What about summer conditions and solar heat radiation? It is clear that the workers did not become blind due to excessive light, but they surely were not happy working in summer under external high temperatures, equally high inside the building. How could solar radiation be mitigated? First, the glass is not transparent but matt, a cheaper version at the time. Matt glass has a slightly lower solar factor. Second, the factory owners used a combination of curtains and cross-natural ventilation to keep temperatures at least not higher than the outside ones. Air conditioned, already invented by Carrier, was of course not an option here, although ventilators were installed later on. It is ironic that exactly the same problem and the same 'natural' mitigation strategy was followed at the Crown Hall building in the IIT campus in Chicago, many years later. Mies van der Rohe was simply learning the same hard lesson again.<br />
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<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/-TtVtHrYqEGk/TtJbikEInyI/AAAAAAAAAS0/B5yBwynmLIU/s1600/Steiff+factory+facade+detail.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="444" src="http://2.bp.blogspot.com/-TtVtHrYqEGk/TtJbikEInyI/AAAAAAAAAS0/B5yBwynmLIU/s640/Steiff+factory+facade+detail.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Vertical section of the double skin facade, taken from Fissabre & Niethammer 2009. Ech glass pane is 3mm thick. The cavity was communicated along the whole height.</td></tr>
</tbody></table><br />
One last detail that struck my attention when preparing this post: where are the stairs? As the plan above shows, there seem to be no stairs inside the factory space. Instead, a ramp was designed that, starting from the ground floor, provided access to the first floor and to the second one from the outside. The main reason for this unusual feature has to be found in the company founder and boss, Ms Steiff's handicap. I can imagine Ms Steiff as a strong minded woman, travelling up and down the ramp in her wheel chair. But there is a second reason, also quite practical. Building permission is given (and taxes are paid) based on the built covered space. A nice internal stairbox would have detracted a noticeable percentage from the net usable area. An external ramp, especially if it was required by a handicapped person, was an excellent alternative that had no impact on the inner space. Again, German passion for efficiency at its most!<br />
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<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/-zaXbSreQ2eA/TtJfcmU7l6I/AAAAAAAAAS8/yF88cgAvMWE/s1600/Steiff+factory+with+ramp+towards+1904.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="416" src="http://2.bp.blogspot.com/-zaXbSreQ2eA/TtJfcmU7l6I/AAAAAAAAAS8/yF88cgAvMWE/s640/Steiff+factory+with+ramp+towards+1904.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">The ramp at the back of the Steiff factory providing access to the first and second floors. Picture taken around 1903-04.</td></tr>
</tbody></table><br />
What was the influence of the Steiff curtain wall in the European architecture? The hard truth is that there were no lessons learnt from this early example of curtain wall application, simply because nobody decided to pay any attention. Why was the Steiff factory so completely ignored at the time?<br />
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<ul><li>First, because the project was not signed by an architect. We now know it couln't be otherwise: an architect would have considered the whole concept too unpalatable. It was not until Gropius developed what he had learnt working for Peter Behrens at the Fagus factory that light was made upon the curtain wall as a respectable facade solution. </li>
<li>Second, the place was not central to anything. Giengen is still today a nice small town, with a German mid-size industrial park devoted to toys and fire-proof systems. It was not in Berlin, the Rühr or Frankfurt.</li>
<li>Third, the company was not AEG or Messerschmidt. Steiff is well-known today but only among toy collectors. It was completely unknown at the beginning of its growth in 1903.</li>
</ul><br />
<ul></ul><ul></ul><table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/-uV9vZTh5KCI/TtKHVJO0NQI/AAAAAAAAATM/stCAjVx0-jA/s1600/Paul+Scheerbart+in+the+Glas+Pavilion+1914.jpg" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="300" src="http://1.bp.blogspot.com/-uV9vZTh5KCI/TtKHVJO0NQI/AAAAAAAAATM/stCAjVx0-jA/s400/Paul+Scheerbart+in+the+Glas+Pavilion+1914.jpg" width="400" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Scheerbart (left) and Bruno Taut at the Glass House, 1914</td></tr>
</tbody></table><div>All said, it is a real pity (or a shame) that architectural critics were so blind about what was happening around them. <a href="http://en.wikipedia.org/wiki/Sigfried_Giedion">Sigfried Giedion</a> was too young, <a href="http://en.wikipedia.org/wiki/Hermann_Muthesius">Muthesius</a> or <a href="http://en.wikipedia.org/wiki/Heinrich_Tessenow">Tessenow</a> were too interested in the handcraft work to notice about steel, glass or modern factories. The glass guru of the time, the poet <a href="http://en.wikipedia.org/wiki/Paul_Scheerbart">Paul Scheerbart</a>, would not write his very influential "Glasarchitektur" until 1914. And by then things had taken another direction. In summary, Richard Steiff was not the right man, not in the right place, and definitely not in the right time to become influential. He had arrived too early. But he still deserves a big part of the credit. Now we know.</div>Ignacio Fernández Sollahttp://www.blogger.com/profile/03918193520738485621noreply@blogger.com3089537 Giengen, Germany48.6225691 10.24474770000006248.5748746 10.167034700000062 48.6702636 10.322460700000061tag:blogger.com,1999:blog-1298203288964657974.post-26835078201562377312010-12-15T00:03:00.005+01:002013-07-03T02:53:44.210+02:00Open | Close: the new Scale series by BirkhauserThe <a href="http://www.birkhauser.ch/">Birkhauser construction books</a> are a source of never-ending information, that grows larger every year. Some may criticize the fact that authors and themes are too German-oriented, understandable for a Basel-Berlin located publisher. But truth is, in my opinion, that if Birkhauser did not exist, we would miss it - and a lot!<br />
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There are many more books there apart from construction. In architecture the list is long and with some big names (Le Corbusier complete works to name just one). But that doesn't make Birkhauser unique: their uniqueness in the world publishing scene is their capacity to push the best known specialists in construction to write, to draw and to expand the knowledge of world readers - in spite of the German touch, or maybe because of it?<br />
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<a href="http://1.bp.blogspot.com/_PnCPTb2jz6w/TQf20zqoSmI/AAAAAAAAAOE/GLSHRdsSLK8/s1600/scale-open-close.jpg" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="400" src="http://1.bp.blogspot.com/_PnCPTb2jz6w/TQf20zqoSmI/AAAAAAAAAOE/GLSHRdsSLK8/s400/scale-open-close.jpg" width="315" /></a>A friend has brought to my attention a book from 2010, titled '<a href="http://www.ribabookshops.com/item/scale-open-close-windows-doors-gates-loggias-filters/68193/">Open | Close. Windows, doors, gates, loggias, filters</a>' This is the first book of a collection called Scale. The second book of the series will be released shortly, 'Enclose I Build'. According to the Editors' foreword, '<i>The Scale series (...) provides illustrations at various different scales and with various degrees of abstraction, wich demonstrate the interrelation of space, design and construction</i>' Judging by the first book of the collection, I would say that the degree of abstraction is a bit too high, and the technical scale is somehow lost in translation.<br />
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Open | Close examines architectural openings, from idea to implementation. The authors did not see the need to have a Contents page, which I see as a bad decision, so here it goes: Introduction - Windows - Filters - Doors and gates - Case studies - Appendix. I was intrigued because Loggias, one of the promises of the title, are not a chapter: in fact, loggia is a word almost non-existing along the book, apart from the title. A real pity.<br />
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The <i>Introduction</i> is poetic to say the least. Issues covered here range from 'Atmosphere' to 'Passageway, threshold and entrance' to 'Spatial openings and intermediate spaces' to 'Ambience and materials'. Luckily it's not too long. The second chapter, <i>Windows</i>, is the longest and at least to me the most disappointing. Aluminium windows and plastic windows share <i>one</i> page of the chapter. Enough. Window hardware (that is, fittings and the like) deals with old drill-in hinges, cremones and espagnolettes used in ancient timber windows, but tilt and turn fittings (covering 85% of all windows installed in Germany, as we learn) don't have a simple illustration or a technical description. Another pity.<br />
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The third chapter, <i>Filters</i>, covers sun and glare control systems, shutters, blinds, curtains and screens. To say 'covers' is a figure of speech: it runs short and passing through all these points. Chapter four is devoted to <i>Doors and gates</i>. Again: fire rated doors and emergency exits (both) can be dealt with in one page, one page meaning a short column of text and one big sketch. Chapter 5 brings us nine <i>Case studies</i>. We had been promised at the Introduction that the examples would be both practical and generally applicable. Maybe, but at least that's not the case with the conversion of the Moritzburg castle in Halle, by Nieto Sobejano. The project is one of the more interesting ones, the problem is that no openings are brought to our attention apart from one small section of a skylight in a nice roof construction - clearly not an opening in itself.<br />
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The book ends with an <i>Appendix</i> that includes several tables and information pages. If your project is in Germany and you don't speak German, it will be of help. There is a list of standards, most of them DIN and EN but not complete and maybe not too reliable either. DIN EN 12208, dealing with watertightness of windows and doors, comes under the heading 'Doors - Thermal insulation'. Would you say DIN EN 14351-1, the product standard for windows and external doors, the standard on which CE mark for windows is given, should be in the list, maybe under the heading 'Windows - Planning in general'? You got it: it's not there - nor anywhere else, but you can enjoy DIN 107 instead, titled 'Left and right designation in construction engineering'. A pity once again.<br />
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<a href="http://4.bp.blogspot.com/_PnCPTb2jz6w/TQf23TPZc5I/AAAAAAAAAOI/e9MKss1t9EE/s1600/Basics+Facade+apertures.jpg" imageanchor="1" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" height="400" src="http://4.bp.blogspot.com/_PnCPTb2jz6w/TQf23TPZc5I/AAAAAAAAAOI/e9MKss1t9EE/s400/Basics+Facade+apertures.jpg" width="280" /></a>Then there is an 'Associations and manufacturers list'. All associations are German. No problem with that, but couldn't the authors (three architects from TU Darmstadt) do some Google digging and add the equivalent British, French and maybe US counterparts? Manufacturers are from... yes. Reynaers is in the list because they have an address in Gladbeck. Technal is not in the list - OK, too French. But Wicona, a great supplier from Ulm providing aluminium window systems all around Europe, is not in the list either! Why?<br />
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My friend paid 49,90€ for this book. I arrived too late to tell him that he should have invested less than half that quantity in buying another Birkhauser book, a much humbler one: <i>Facade Apertures</i> from the Basics series. Its cost? 12,90€. The amount of valuable information? Quite the same, with less nice colour images for sure. This - having arrived late with my advice - is the biggest pity indeed.Ignacio Fernández Sollahttp://www.blogger.com/profile/03918193520738485621noreply@blogger.com24tag:blogger.com,1999:blog-1298203288964657974.post-63570530331613633812010-12-04T10:32:00.021+01:002010-12-13T00:17:26.617+01:00ThyssenKrupp Quarter facades: a giant's gentle skinSome great buildings pass unnoticed below the radar of architectural intelligentsia. And not because they are small or built in lost places, but because they are too 'client oriented'. If a corporation is satisfied with their new HQ building, its architectural quality must have been low, or so the thinking goes. This post describes a recently finished great group of buildings - two times great, since they are both architecturally compelling and they perfectly reflect their owner and user's vision. If this group of buildings is interesting in a number of ways, one of them is the facade treatment, as I will try to demonstrate here below.<br />
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<div class="separator" style="clear: both; text-align: center;"><a href="http://4.bp.blogspot.com/_PnCPTb2jz6w/TPuwvtrmfmI/AAAAAAAAAL8/2aoKxIolw1c/s1600/general+view.png" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="274" src="http://4.bp.blogspot.com/_PnCPTb2jz6w/TPuwvtrmfmI/AAAAAAAAAL8/2aoKxIolw1c/s640/general+view.png" width="640" /></a></div><br />
During several decades the architectural landscape of the Ruhr Valley towns in Germany has been dominated by neglected brown fields, industrial ruins and run-down postwar buildings. That is now becoming a thing of the past as architects from all over Europe complete their projects in the former coal-mining region.<br />
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<div class="separator" style="clear: both; text-align: center;"><a href="http://2.bp.blogspot.com/_PnCPTb2jz6w/TPuxA0OrTyI/AAAAAAAAAMA/iO3XyuossC4/s1600/stammhaus.jpg" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="200" src="http://2.bp.blogspot.com/_PnCPTb2jz6w/TPuxA0OrTyI/AAAAAAAAAMA/iO3XyuossC4/s400/stammhaus.jpg" width="400" /></a></div>The <a href="http://www.thyssenkrupp.com/quartier/en/quarter/">ThyssenKrupp Quarter</a> in Essen is part of a 230-hectare downtown area known as the Krupp belt. The site, kept for years as a wasteland, is a historic place. In 1818, Friedrich Krupp founded a cast steelworks on the same spot, which his son Alfred turned into a global company. Railway tracks were produced here for the United States, and less exciting but quite effective canons were casted in the area for two world wars. It is a place in German history that triggers mixed emotions to say the least. A less known but more interesting tip for architects: the huge 'gerberettes' designed by Rice, Piano and Rogers for the Pompidou Centre in Paris were also built at the Krupp furnaces, not far from Essen. Krupp was the only company in Europe who stood to the challenge of producing the big cast steel pieces that were to play a significant role in the structural concept of the Beaubourg.<br />
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<div class="separator" style="clear: both; text-align: center;"><a href="http://1.bp.blogspot.com/_PnCPTb2jz6w/TPuyGQ0AKYI/AAAAAAAAAME/24lD3V4p1Cg/s1600/ThyssenKrupp+Quarter+masterplan.png" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="262" src="http://1.bp.blogspot.com/_PnCPTb2jz6w/TPuyGQ0AKYI/AAAAAAAAAME/24lD3V4p1Cg/s640/ThyssenKrupp+Quarter+masterplan.png" width="640" /></a></div><br />
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ThyssenKrupp has built its new headquarters in this historic part of Essen at a total cost of 300 million euros. The technology giant, which employs 173,000 personnel in 80 countries, has no interest for skyscrapers. ThyssenKrupp’s chief expectation during the competition was that architects made the essence of its brand visible: transparency, innovation and far-ranging versatility. With the bulk of the masterplan finished this last summer, corporate culture and German industrial power welcome a new symbol. <br />
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<div class="separator" style="clear: both; text-align: center;"><a href="http://2.bp.blogspot.com/_PnCPTb2jz6w/TPuy7WZhx1I/AAAAAAAAAMI/W3BHN37cvIM/s1600/JSWD-Q1-ThyssenKrupp.png" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="300" src="http://2.bp.blogspot.com/_PnCPTb2jz6w/TPuy7WZhx1I/AAAAAAAAAMI/W3BHN37cvIM/s400/JSWD-Q1-ThyssenKrupp.png" width="400" /></a></div>Chaix & Morel et associés (Paris) and JSWD Architects (Cologne) won the competition for the campus buildings and developed the ThyssenKrupp Quarter for a working population of 2,000 employees. There is ample space for them here. A 200 meter-long and 30 meter-wide pool forms an axis along which various buildings and generously laid-out boulevards appear. It is quiet around here, too. Cars disappear into car parks and subterranean garages around the plot. All deliveries are conducted below ground. Above this, 68 trees from five continents form a boulevard. There are large expanses of lush green lawn without bushes or perennials. The important aspects here are distance, silence and solemnity. Peter Drucker would have salivated in awe: this is the spirit of the new corporation, built to last.<br />
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<div class="separator" style="clear: both; text-align: center;"><a href="http://1.bp.blogspot.com/_PnCPTb2jz6w/TPuzbWLy6BI/AAAAAAAAAMM/EWPbJnmUNIk/s1600/Q1+main+facade.png" imageanchor="1" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" height="277" src="http://1.bp.blogspot.com/_PnCPTb2jz6w/TPuzbWLy6BI/AAAAAAAAAMM/EWPbJnmUNIk/s400/Q1+main+facade.png" width="400" /></a></div>The main building, known as Q1 and officially inaugurated in June, has a flexible facade layer made up of 400,000 stainless steel slats. This system aims to make air conditioning redundant. A weather station on the roof sends signals to a computer that steers the rotation of the facade slats. The design makes use of the material Nirosta, one of the concern’s branded products. ThyssenKrupp also aims to improve the cladding of high-rise buildings, and replace expensive aluminum profiles. To this end, the company has developed steel sheeting with a zinc and magnesium coating.<br />
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There are three elements that deserve to be described in more detail in this post: the glass mullionless curtain walls in the centre of Q1, the sunshades at the external office areas also in Q1, and the flat-rolled steel cladding of buildings Q1 (inside the atrium), Q2 forum, Q5 and Q7 (as the main facade cladding). Let's go with the description, one at a time.<br />
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<b>Panoramic windows at the atrium</b><br />
The large atrium area of Q1 shimmers as a result of its pearl-metallic gold color internal cladding. But it is primarily the expansive volume of space that captivates. The 50 meter-high building, bonded from two L-shaped structures, is dominated by 'panorama windows', in fact two large tensed cable curtain walls. Both glass constructions are 28 meter high and 26 meter wide. The design and engineering of the panorama windows was done by <a href="http://www.wernersobek.com/">Werner Sobek</a> from Stuttgart. The facade contractor was <a href="http://hefi-glaskonstruktiv.de/">Hefi Glaskonstructiv</a> from Talheim, Germany.<br />
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<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/_PnCPTb2jz6w/TPu0pP-yaiI/AAAAAAAAAMQ/YR8CE05qTbA/s1600/panorama+window+from+inside.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="640" src="http://1.bp.blogspot.com/_PnCPTb2jz6w/TPu0pP-yaiI/AAAAAAAAAMQ/YR8CE05qTbA/s640/panorama+window+from+inside.png" width="480" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span class="Apple-style-span" style="font-family: Times, 'Times New Roman', serif;"><span class="Apple-style-span" style="font-size: x-small;"><i>View of the main axis pool through the panorama window at Q1</i></span></span></td></tr>
</tbody></table>A steel pre-stressed cable net system holds the individual glass panes in place. Each double glass unit is 2.15m wide x 3.60m high, with clamps at the corners and mid height to connect it to the vertical and horizontal steel cables. Pre-stressing in two axes made it possible to eliminate complicated transitional details to the adjacent facade structures. In the vertical direction, with a grid dimension of 2.15m, the grid is composed of pairs of pre-stressed cables with a diameter of 30mm each. They are fixed to a three-story steel truss below the building’s 11th floor. The horizontal net structure, attached at the ends to the story floors, consists of one pre-stressed steel cable every 3.60m, with a diameter of 32mm. The vertical cable disposition in pairs allows the transfer of the glass self-weight via a force couple - tension and compression - into the pre-stressed cables. The horizontal pre-stress per story is 34 tons, while the vertical pre-stress connection is 2 x 15 tons. To transmit these forces the engineers from Werner Sobek chose carbon steel of grade S355. Compared with stainless steel, carbon steel displays a higher strength and a lower thermal expansion. The cables have a tensile strength of 1770N/mm2.<br />
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The structural solution followed here is quite similar to the Lufthansa Aviation Centre in Frankfurt, also by Werner Sobek, although in Frankfurt the only load-bearing elements are the vertically tensioned cables.<br />
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</div><table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right; margin-left: 1em; text-align: right;"><tbody>
<tr><td style="text-align: center;"><a href="http://4.bp.blogspot.com/_PnCPTb2jz6w/TPu1GRxShuI/AAAAAAAAAMU/i5auBorx6JU/s1600/panorama+window+lateral.png" imageanchor="1" style="clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="300" src="http://4.bp.blogspot.com/_PnCPTb2jz6w/TPu1GRxShuI/AAAAAAAAAMU/i5auBorx6JU/s400/panorama+window+lateral.png" width="400" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span class="Apple-style-span" style="font-family: Times, 'Times New Roman', serif;"><i><span class="Apple-style-span" style="font-size: x-small;">Atrium with panorama window to the left</span></i></span></td></tr>
</tbody></table><div>The choice of glass was critical too: on the one hand it had to have solar control, while on the other it had to be clear with as little tinting as possible. To achieve the aim of maximum-possible transparency, a custom solution featuring insulated clear glass panes was selected. The structure is as follows: a) 12mm single-pane safety glass, b) 16mm inter-pane space, c) 2 x 8mm laminated safety glass with 1.52mm PVB film for solar control. The type of glazing chosen and the reduced support structure have resulted in an only 45 mm thick membrane that appears completely dematerialized. Despite being so thin, the glazed membrane met all thermal insulation requirements. I have not found any reference to argon fill in the glass cavity, but assume it is the case or the U-value would have been too high.</div><div><br />
</div><div>The images below show the section, elevation and concept details of the glass fixings.</div><table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/_PnCPTb2jz6w/TPu5UVdyp0I/AAAAAAAAAMc/_WXFFwr1v6c/s1600/TK+Q1+section+and+glass+elevation.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="368" src="http://1.bp.blogspot.com/_PnCPTb2jz6w/TPu5UVdyp0I/AAAAAAAAAMc/_WXFFwr1v6c/s640/TK+Q1+section+and+glass+elevation.png" width="640" /></a></td></tr>
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</tbody></table><div><div style="text-align: center;"><span class="Apple-style-span" style="font-size: x-small;"><span class="Apple-style-span" style="font-family: Times, 'Times New Roman', serif;"><i>ThyssenKrupp Q1 building: vertical section and panorama window glass elevation</i></span></span></div></div><div><span class="Apple-style-span" style="font-family: Times, 'Times New Roman', serif;"><span class="Apple-style-span" style="font-size: x-small;"><i><br />
</i></span></span></div><div><table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://4.bp.blogspot.com/_PnCPTb2jz6w/TPyMflddFDI/AAAAAAAAAMo/0zQ8hXswikw/s1600/TK+Q1%252C+panoramic+window+vertical+section+detail.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="356" src="http://4.bp.blogspot.com/_PnCPTb2jz6w/TPyMflddFDI/AAAAAAAAAMo/0zQ8hXswikw/s640/TK+Q1%252C+panoramic+window+vertical+section+detail.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span class="Apple-style-span" style="font-size: x-small;"><span class="Apple-style-span" style="font-family: Times, 'Times New Roman', serif;"><i>ThyssenKrupp Q1 building: vertical detail of fixing at glass crossing. Two cables run vertical, one cable (sectioned) runs horizontal. All screw heads are embedded on the cast steel piece.<span class="Apple-style-span" style="font-family: Geneva; font-size: small; font-style: normal;"> </span></i></span></span></td></tr>
</tbody></table><table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://4.bp.blogspot.com/_PnCPTb2jz6w/TPyMj6M69iI/AAAAAAAAAMs/2BBtk_ylIDU/s1600/TK+Q1%252C+panoramic+window+horizontal+section+detail.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="640" src="http://4.bp.blogspot.com/_PnCPTb2jz6w/TPyMj6M69iI/AAAAAAAAAMs/2BBtk_ylIDU/s640/TK+Q1%252C+panoramic+window+horizontal+section+detail.png" width="628" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span class="Apple-style-span" style="font-size: x-small;"><span class="Apple-style-span" style="font-family: Times, 'Times New Roman', serif;"><i>ThyssenKrupp Q1 building: horizontal detail of fixing at glass crossing, and elevation detail of the external clamp. Two cables run vertical (sectioned), one cable runs horizontal.</i></span></span></td></tr>
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<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/_PnCPTb2jz6w/TPu1Tp-tcSI/AAAAAAAAAMY/zV-CZOlb378/s1600/panorama+glass+detail.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="360" src="http://1.bp.blogspot.com/_PnCPTb2jz6w/TPu1Tp-tcSI/AAAAAAAAAMY/zV-CZOlb378/s400/panorama+glass+detail.png" width="400" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span class="Apple-style-span" style="font-family: Times, 'Times New Roman', serif;"><span class="Apple-style-span" style="font-size: x-small;"><i>The panorama windows viewed from inside</i></span></span></td></tr>
</tbody></table><div>It’s not just the two panoramic windows that contribute to the amount of light that floods the atrium: there is also a large window opening in the atrium roof, supported by a cable net. Its dual-curved outer skin measures approximately 21 x 21m.</div><div><br />
</div><div>The technology of pre-stressed cable net facades is not new, and it's a very German one. If you are interested, there is a good summary in pages 235 to 243 of the highly recommended thesis by Mic Patterson, '<a href="http://arch.usc.edu/content/pages/cm/uploadedmedia/michael_robert_patterson_(2008)_structural_glass_facades1242159283229.pdf">Structural glass facades: a unique building technology</a>'. The first and still best known example of this glass wall system is the lobby of the Kempinski Hotel at the Munich airport, designed by Helmut Jahn and engineered by <a href="http://www.sbp.de/en/html/projects/detail.html?id=9">Schlaich, Bergemann & Parters</a>. The hotel lobby was completed in 1993 and still looks amazing 17 years afterwards. The cable net grid in Munich is much smaller than the one in Essen, but there is only one cable per direction, making the knots less visually imposing than those of the ThyssenKrupp atrium. One could say that the Sobek version is more imposing in size and less innovative in the fixing details than its SBP's counterpart. But Munich was a much less rigid, monolithic glass, not an insulated screen. In any case, at least to me, the real interest of Q1 does not lay on the panorama windows, but on a much humbler element: the sunshades of the office space all around the building.</div><br />
<b>Sun-shading movable slats</b><br />
Our industry has been strongly discussing for some years about the energy irrelevance of double skin glass facades. Their former advantage in reducing U-values has been equaled by the triple-glass units with argon-filled cavities and high-performant coatings developed in the last decade. On the other hand, g-value or heat gain coefficient (the % of solar radiation that penetrates through the glass) remains as a serious problem for office buildings in summer period. Renzo Piano was the first one in introducing the 'mediterranean double skin', that is, a continuous glass facade with a set of sunshades on the outside for solar protection. An energy simulation study presented by Mikkel Kragh and Annalisa Simonella from Arup Facade Engineering at ICBEST 2007 has got to the same conclussion: <a href="http://www.facadeengineeringsociety.org/news/SFE%20elevation%203.pdf">there is no direct correlation between U-value and overall energy performance in a building with high internal heat gains</a>, as an office building. In other words, the main driver is exposure to solar radiation.<br />
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<div class="separator" style="clear: both; text-align: center;"><a href="http://4.bp.blogspot.com/_PnCPTb2jz6w/TPyaZon5tyI/AAAAAAAAAMw/QfZ5A1bLieg/s1600/sonnenschutz.jpg" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="320" src="http://4.bp.blogspot.com/_PnCPTb2jz6w/TPyaZon5tyI/AAAAAAAAAMw/QfZ5A1bLieg/s640/sonnenschutz.jpg" width="640" /></a></div><br />
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The best answer from a energy and daylight perspective, even in a cold climate as the Ruhr Valley, is to combine a lowish U<span class="Apple-style-span" style="font-size: xx-small;">w</span>-value (around 1,2W/m2ºK for example, achievable with double glass units and high-performant thermally broken profiles) with an effective sunscreen. 'Effective' here means a screen that reduces solar gains when there is direct solar radiation but lets daylight in when there isn't. That is, a moveable sunscreen. Et voilà: this is the solution applied to ThyssenKrupp Q1 facades.<br />
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<div><table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/_PnCPTb2jz6w/TPya3wbb9oI/AAAAAAAAAM0/TyRy_HgAeZI/s1600/28850132_33d2501ec6%255B1%255D.jpg" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="640" src="http://2.bp.blogspot.com/_PnCPTb2jz6w/TPya3wbb9oI/AAAAAAAAAM0/TyRy_HgAeZI/s640/28850132_33d2501ec6%255B1%255D.jpg" width="424" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span class="Apple-style-span" style="font-family: Times, 'Times New Roman', serif;"><span class="Apple-style-span" style="font-size: x-small;"><i>Multiple image with fins at different angles from 0º to 90º</i></span></span></td></tr>
</tbody></table></div>The sun-shading concept was suggested by the architects and developed by the <a href="http://www.ise.fraunhofer.de/welcome-to-the-web-pages-of-the-fraunhofer-institute-for-solar-energy-systems?set_language=en&cl=en">Fraunhofer Institute for Solar Energy Systems</a> in Freiburg. The energy study came out with a proposal to provide a constant horizontal overhang - useful for summer protection and as a catwalk - combined with a vertical set of twisting fins. The fins would twist to achieve an adjustable position between 0º (parallel to the facade: total direct radiation blocking) and 90º (perpendicular to the facade: maximum daylight penetration).<br />
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The great idea in this concept was to create a vertical fin made of horizontal cantilevered slats that were connected to a central stud, something similar to vertebrae in a spine. The cantilevered fins at each side of the stud can twist independently, as arms that rotate from widely open (0º) to parallel and intertwinned (90º). The final touch was to provide a shape for the fins that was non-rectangular, thus creating an interesting texture as the fins rotate along the day.<br />
The sunshade elements have been manufactured by <a href="http://www.thyssenkrupp-nirosta.de/en/">ThyssenKrupp Nirosta</a> (the company branch for stainless steel) using a chromium- nickel-molybdenum stainless steel with high corrosion resistance called Nirosta 4404 (that is, EN 1.4404, equivalent to AISI 316L).<br />
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<div><table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right; margin-left: 1em; text-align: right;"><tbody>
<tr><td style="text-align: center;"><a href="http://4.bp.blogspot.com/_PnCPTb2jz6w/TPye5MMOgoI/AAAAAAAAAM4/aBEylGgRSfw/s1600/28850129_cad35d94a0%255B1%255D.jpg" imageanchor="1" style="clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="640" src="http://4.bp.blogspot.com/_PnCPTb2jz6w/TPye5MMOgoI/AAAAAAAAAM4/aBEylGgRSfw/s640/28850129_cad35d94a0%255B1%255D.jpg" width="424" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span class="Apple-style-span" style="font-size: x-small;"><span class="Apple-style-span" style="font-family: Times, 'Times New Roman', serif;"><i>The movable fins from inside, with the horizontal catwalk</i></span></span></td></tr>
</tbody></table></div>Each slat is ground on one side and sandblasted on the other. The slats thus appear to be matt or glossy depending on the point of view and incidence of light. The slat surface directs the incoming light indoors in such a way that the offices remain bright enough even if the sun protection is closed.<br />
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The manufacturing of the sun protection system must have been demanding. First, the metal strips were processed by ThyssenKrupp Umformtechnik, the group's automotive manufacturing unit. Then, <a href="http://www.frener-reifer.com/En/New/ThyssenKrupp-Headquarter/default.htm">Frener & Reifer</a>, the facade contractor from South Tyrol mounted 116 to 160 slats onto each axis to form electrically driven slat packages. In the process, it was important that the slats remain movable in the center axis and react precisely to the signals of the electrical drive. It's funny that Frener & Reifer motto is 'Starting where others stop', completely adequate to this particular job. The facade contractors did also install the inner curtain wall, made with Schüco elements. Both skins in Q1, curtain wall and fins, are approximately 7,800m2 each.<br />
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The <a href="http://www.frener-reifer.com/resources/Neu/ThyssenKruppHq.mov">virtual animation</a> at the Frener & Reifer page shows the movement game better than my words. The programming is really sensitive: the control system not only detects the seasonal sun position, but also knows what the current weather is like due to the data of a weather station located on the roof of Q1 building. On cloudy days, for example, all the slats will be turned outwards so that the sun shades remain open. Even when the slats are closed directly in front of the facade, employees can open the windows and access for maintenance is always possible.<br />
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<div class="separator" style="clear: both; text-align: center;"><a href="http://2.bp.blogspot.com/_PnCPTb2jz6w/TPyfcco35gI/AAAAAAAAAM8/5cexAGvJmMc/s1600/tmpE86D.tmp_tcm20-604782%255B1%255D.jpg" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="288" src="http://2.bp.blogspot.com/_PnCPTb2jz6w/TPyfcco35gI/AAAAAAAAAM8/5cexAGvJmMc/s640/tmpE86D.tmp_tcm20-604782%255B1%255D.jpg" width="640" /></a></div>There are in total a number of 1,600 motors to activate the fins movement. This seems as a maintenance nightmare, but it doesn't have to be so. Movable facade elements are more and more common lately, with motor costs going down and system reliability moving up every year.<br />
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This is a revolutionary design move, not in concept but in results: I suspect we will see many more moveable sun-shades in the near future. There is an interesting joint venture between Buro Happold and Hoberman, called <a href="http://www.adaptivebuildings.com/index.html">Adaptative Building Initiative</a>, that provides nothing but moveable facade elements to control solar gains and light levels at the same time.<br />
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<div><strong>External steel cladding</strong></div><div>Sheet metal has long been considered a second rate cladding material – an impression the buildings of the ThyssenKrupp Quarter had to change. The final image of the buildings around Q1, finely glimmering in a champagne hue of metallic elements, consist of nothing other than sheets of steel.</div><div style="border-bottom: medium none; border-left: medium none; border-right: medium none; border-top: medium none;"><span class="Apple-style-span" style="color: #333333; font-family: Arial, Helvetica, sans-serif; font-size: 11px; line-height: 16px;"></span><br />
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<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/_PnCPTb2jz6w/TPzSlrCZOZI/AAAAAAAAANE/vgCATZiVF_w/s1600/TKQ%252C+Q2+forum+facade.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="233" src="http://2.bp.blogspot.com/_PnCPTb2jz6w/TPzSlrCZOZI/AAAAAAAAANE/vgCATZiVF_w/s640/TKQ%252C+Q2+forum+facade.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span class="Apple-style-span" style="font-family: Times, 'Times New Roman', serif;"><i><span class="Apple-style-span" style="font-size: x-small;">ThyssenKrupp Quarter, Q2 Forum building facade clad in coil coated steel sheets.</span></i></span></td></tr>
</tbody></table> <br />
<div style="border-bottom: medium none; border-left: medium none; border-right: medium none; border-top: medium none;">Not just any sheet steel but a high-quality, fine sheet steel organically refined using a coil coating method. Fine sheet metal, coated using the hot-dip method, can be shaped, welded and painted. The 3m long and 0.67m wide, chamfered steel panels of the Quarter are resistant to wind, weather and UV radiation. Here, one percent of magnesium is added to the molten zinc for the fine sheet metal. As a result, improved corrosion protection is achieved with a thinner coating, which means that the valuable raw material zinc can be used sparingly.</div> <br />
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<tr><td style="text-align: center;"><div style="border-bottom: medium none; border-left: medium none; border-right: medium none; border-top: medium none;"><a href="http://3.bp.blogspot.com/_PnCPTb2jz6w/TPzTLxaE06I/AAAAAAAAANI/aNO8d4pbN6Q/s1600/TKQ%252C+mock-up+of+Q2+facade.jpg" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="300" src="http://3.bp.blogspot.com/_PnCPTb2jz6w/TPzTLxaE06I/AAAAAAAAANI/aNO8d4pbN6Q/s400/TKQ%252C+mock-up+of+Q2+facade.jpg" width="400" /></a></div></td></tr>
<tr><td class="tr-caption" style="border-bottom: medium none; border-left: medium none; border-right: medium none; border-top: medium none; text-align: center;"><span class="Apple-style-span" style="font-family: Times, 'Times New Roman', serif;"><i><span class="Apple-style-span" style="font-size: x-small;">Q2 Forum facade mock-up on site</span></i></span></td></tr>
</tbody></table>The fine sheet metal, with a thickness of 0.8 to 1.2mm, is more affordable than a comparable facade element made of aluminum sheets of 3mm, at least so the ThyssenKrupp guys say. The material is called <a href="http://www.thyssenkrupp-steel-europe.com/en/publikationen/produktinformationen/organisch_band_blech.jsp">PLADUR ZM Premium steel</a>; used as cladding for the walls of the atrium inside Q1, the interior of the ground-floor lobbies in Q2, Q5 and Q7 buildings, and the exterior facade areas on Q2 forum, Q5 and Q7. The material owes its appearance to a multi-layer coating in a color named Pearl Metallic Gold. Thanks to special pigments, the color shade of the surface changes depending on light conditions and the angle from which it is viewed. The term “Premium” refers mainly to the quality of the top coat, while the abbreviation ZM means that the surface of the steel is first protected against corrosion with a zinc-magnesium alloy coating before the paint system is applied. This alloy provides roughly twice the corrosion protection effect of conventional hot-dip galvanizing.<br />
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<tr><td style="border-bottom: medium none; border-left: medium none; border-right: medium none; border-top: medium none; text-align: center;"><div style="border-bottom: medium none; border-left: medium none; border-right: medium none; border-top: medium none;"><a href="http://3.bp.blogspot.com/_PnCPTb2jz6w/TPzTuheH83I/AAAAAAAAANM/oHHkf-QykuI/s1600/TKQ%252C+Q5+and+Q7+facades.jpg" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="474" src="http://3.bp.blogspot.com/_PnCPTb2jz6w/TPzTuheH83I/AAAAAAAAANM/oHHkf-QykuI/s640/TKQ%252C+Q5+and+Q7+facades.jpg" width="640" /></a></div></td></tr>
<tr><td class="tr-caption" style="border-bottom: medium none; border-left: medium none; border-right: medium none; border-top: medium none; text-align: center;"><span class="Apple-style-span" style="font-family: Times, 'Times New Roman', serif;"><i><span class="Apple-style-span" style="font-size: x-small;">TKQ, Q5 and Q7 facades</span></i></span></td></tr>
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</div><div style="border-bottom: medium none; border-left: medium none; border-right: medium none; border-top: medium none;"><span class="Apple-style-span" style="color: #333333; font-family: Arial, Helvetica, sans-serif; font-size: 11px; line-height: 16px;"></span>It's fair to record that the façade area consultant for the Quarter has been <a href="http://priedemann.de/flash.html">Priedemann Fassadenberatung</a> from Berlin. No information can be found at their Webpage about the project or their contribution though.</div></div><div style="margin: 0px 0px 12px; padding-bottom: 0px; padding-left: 0px; padding-right: 0px; padding-top: 0px; text-indent: 0px;"></div><div style="margin: 0px 0px 12px; padding-bottom: 0px; padding-left: 0px; padding-right: 0px; padding-top: 0px; text-indent: 0px;"></div><div style="margin: 0px 0px 12px; padding-bottom: 0px; padding-left: 0px; padding-right: 0px; padding-top: 0px; text-indent: 0px;"></div>Let me finish this long post in silence. No more words - there have been too many! Just some selected images of Q1 and the sun-shading slats that struck me when I first knew about this project. In awe...</div><div><div class="separator" style="clear: both; text-align: center;"></div><br />
<div class="separator" style="clear: both; text-align: center;"><a href="http://4.bp.blogspot.com/_PnCPTb2jz6w/TPzWyHuLxTI/AAAAAAAAANs/k2xbtoX6Z1U/s1600/ThyssenKrupp_Q1_%252405%255B1%255D.jpg" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="480" src="http://4.bp.blogspot.com/_PnCPTb2jz6w/TPzWyHuLxTI/AAAAAAAAANs/k2xbtoX6Z1U/s640/ThyssenKrupp_Q1_%252405%255B1%255D.jpg" width="640" /></a></div><div class="separator" style="clear: both; text-align: center;"><a href="http://3.bp.blogspot.com/_PnCPTb2jz6w/TPzXB0MITPI/AAAAAAAAANw/odfe_On5VrE/s1600/tmpE876_tmp_tcm20-604791.jpg" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="426" src="http://3.bp.blogspot.com/_PnCPTb2jz6w/TPzXB0MITPI/AAAAAAAAANw/odfe_On5VrE/s640/tmpE876_tmp_tcm20-604791.jpg" width="640" /></a></div><div class="separator" style="clear: both; text-align: center;"><a href="http://1.bp.blogspot.com/_PnCPTb2jz6w/TPzV_6p1cQI/AAAAAAAAANQ/A23vwENVZv8/s1600/28850137_d8cd265609%255B1%255D.jpg" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="556" src="http://1.bp.blogspot.com/_PnCPTb2jz6w/TPzV_6p1cQI/AAAAAAAAANQ/A23vwENVZv8/s640/28850137_d8cd265609%255B1%255D.jpg" width="640" /></a></div></div><div class="separator" style="border-bottom: medium none; border-left: medium none; border-right: medium none; border-top: medium none; clear: both; text-align: center;"></div><div class="separator" style="border-bottom: medium none; border-left: medium none; border-right: medium none; border-top: medium none; clear: both; text-align: center;"></div><div class="separator" style="border-bottom: medium none; border-left: medium none; border-right: medium none; border-top: medium none; clear: both; text-align: center;"></div><div class="separator" style="border-bottom: medium none; border-left: medium none; border-right: medium none; border-top: medium none; clear: both; text-align: center;"></div>Ignacio Fernández Sollahttp://www.blogger.com/profile/03918193520738485621noreply@blogger.com24tag:blogger.com,1999:blog-1298203288964657974.post-52638479575181798092010-11-28T18:06:00.003+01:002011-11-28T23:31:03.445+01:00Building up the perfect wall<div class="separator" style="clear: both; text-align: center;"></div>There are dozens of facade consultants, facade engineers or building envelope specialists Webpages out there. Many of them are being listed in this blog, in the column <b>Engineers & Facade consultants</b>. There is a constant in these pages: you won't find almost any information about what we facade specialists really do for a living. We don't write there. We have no opinions about our field of experience. We seem to be on the hyperspace trying to convince potential clients that we are the right folks for them, just because our Webpage - not designed by us - looks great or professional. The fact that it almost always looks boring doesn't seem to bother us.<br />
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<div class="separator" style="clear: both; text-align: center;"><a href="http://2.bp.blogspot.com/_PnCPTb2jz6w/TPIbKwNjqoI/AAAAAAAAALY/GUQdHglPJ4o/s1600/Building+Science+Corporation.jpg" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="327" src="http://2.bp.blogspot.com/_PnCPTb2jz6w/TPIbKwNjqoI/AAAAAAAAALY/GUQdHglPJ4o/s400/Building+Science+Corporation.jpg" width="400" /></a></div>There is one exception at least, one that clearly jumps above all others. This post is dedicated to a bunch of building science specialists - mainly building envelope related - who are brave enough to write and say what they think and do. Their Webpage is called <a href="http://www.buildingscience.com/">Buildingscience.com</a>. Against all odds, it's not another governmental agency or something paid by a guild of construction materials suppliers. Building Science Corporation is a firm of building consultants and architects, located in Massachusetts with a branch in Ontario. They specialize in building technology consulting, more specifically in preventing and resolving problems related to building design, construction and - yes - operation. They seem to be experts in energy efficiency, buildings retrofit, moisture dynamics, indoor air quality and building failure investigations.<br />
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The difference between this team and other building envelope specialists is the people they have and the way they market themselves. Two of the principals, Joseph Lstiburek and John Straube, are also the most active writers of articles in the <a href="http://www.buildingscience.com/index_html">information</a> part of the Webpage. These guys sum up a huge field experience with strong academic and research roots, combine knowledge with an entertaining writing style, and deal with issues one rarely finds treated with such clarity. Lstiburek founded the company, Straube joined later. Lstiburek seems to be the one with practical roots, reinforced by being part of the 'Building America' program at the US Department of Energy. Straube seems to be the professor in the team, teaching building science in the Civil Engineering Department and School of Architecture at the University of Waterloo, Canada.<br />
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<a href="http://4.bp.blogspot.com/_PnCPTb2jz6w/TI8dPkdMEJI/AAAAAAAAADI/MuRmSTMuguk/s1600/masonry_figure_06.jpg" imageanchor="1" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" height="400" src="http://4.bp.blogspot.com/_PnCPTb2jz6w/TI8dPkdMEJI/AAAAAAAAADI/MuRmSTMuguk/s400/masonry_figure_06.jpg" width="330" /></a><br />
There are several document files available at their Webpage. The most interesting papers can be found under the labels <a href="http://www.buildingscience.com/doctypes/digests">Building Science Digests</a> (BSD), <a href="http://www.buildingscience.com/doctypes/insights">Building Science Insights</a> (BSI), <a href="http://www.buildingscience.com/doctypes/guides-and-manuals">Guides and Manuals</a> (GM) and <a href="http://www.buildingscience.com/doctypes/reports">Research Reports</a> (RR). There is also a complete <a href="http://www.buildingscience.com/glossary?search_letter=a">Glossary</a> of Building Science terms. Digests and Insights are much less dense and really fun to read. Let's have a look for instance at <a href="http://www.buildingscience.com/documents/insights/bsi-005-a-bridge-too-far">BSI 005: A bridge too far</a> by Joseph Lstiburek. The topic is obviously thermal bridges. You can find sentences as these:<br />
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<i>For a bunch of supposedly clever folks we sure do dumb things. One of the big ideas of the past couple of decades or so is to keep the heat out during cooling and keep the heat in during heating. The better we are at this the less energy we need to use to condition the interior. Apparently this concept has not caught on. (...) If an alien from another planet looked at our construction practices he would conclude that we have too much heat in buildings and we want to reject that heat to the outside.</i><br />
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<div>The paper is illustrated with images as clear as the one below (the caption has been copied from the original):<br />
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<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/_PnCPTb2jz6w/TPIWMLucZmI/AAAAAAAAALU/NQ6swDwf6n8/s1600/ugly%252C+bad+and+good.jpg" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="298" src="http://2.bp.blogspot.com/_PnCPTb2jz6w/TPIWMLucZmI/AAAAAAAAALU/NQ6swDwf6n8/s640/ugly%252C+bad+and+good.jpg" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span class="Apple-style-span" style="border-collapse: collapse; color: #333333; line-height: 15px;"><span style="font-weight: bold;"><i><span class="Apple-style-span" style="font-size: x-small;"><span class="Apple-style-span" style="font-family: Times, 'Times New Roman', serif;">"Clint Eastwood" Thermodynamics</span></span></i></span><i><span class="Apple-style-span" style="font-size: x-small;"><span class="Apple-style-span" style="font-family: Times, 'Times New Roman', serif;">—“The Good” uses offsets and exterior insulation. “The Bad” only uses exterior insulation. “The Ugly” uses neither.</span></span></i></span> </td></tr>
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Why can't we be as clear as these folks when discussing about things we all know - and can be measured?<br />
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Let's go back to the paper that bears the name of this post, <a href="http://www.buildingscience.com/documents/insights/bsi-001-the-perfect-wall">BSI 001: The perfect wall</a>, another example of must read building envelope science. The author is again our entertaining but precise Joseph Lstiburek:<br />
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<i>The perfect wall is an environmental separator—it has to keep the outside out and the inside in. (...) Today walls need four principal control layers—especially if we don’t build out of rocks. They are presented in order of importance: a) a rain control layer, b) an air control layer, c) a vapor control layer, and d) a thermal control layer.</i><br />
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<div><a href="http://4.bp.blogspot.com/_PnCPTb2jz6w/TPJNmX3isKI/AAAAAAAAALc/j7tQSNqUAxo/s1600/perfect+wall+concept.jpg" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" src="http://4.bp.blogspot.com/_PnCPTb2jz6w/TPJNmX3isKI/AAAAAAAAALc/j7tQSNqUAxo/s1600/perfect+wall+concept.jpg" /></a>In concept the perfect wall (see image to the left) should have the rainwater control layer, the air control layer, the vapor control layer and the thermal control layer <i>on the exterior</i> of the structure. The cladding function is principally to act a an ultra-violet screen and a first rain screen. And yes, architects also consider the aesthetics of the cladding to be important.</div><div><br />
</div><div>At this point Straube goes for a second to Canada, and refers (without mentioning their names) to the seminal works of the Norwegian O. Birkeland and the Canadian G.K. Garden about the concept of rain screen cladding and the <a href="http://www.nrc-cnrc.gc.ca/eng/ibp/irc/cbd/building-digest-40.html">control of rain penetration</a>. I will dedicate a post to these guys and their papers, written in the first half of the 60s, since their influence is greater today than at the time of writing. Another old Canadian professor is cited here, N.B. Hutcheon, whose <a href="http://www.nrc-cnrc.gc.ca/eng/ibp/irc/cbd/building-digest-50.html">Principles Applied to an Insulated Masonry Wall</a> (1964) are also completely up to date. The images shown here below, taken from Hutcheon, still resonate in their clarity.</div><div><br />
</div><div class="separator" style="clear: both; text-align: center;"><a href="http://2.bp.blogspot.com/_PnCPTb2jz6w/TPJX8M16PLI/AAAAAAAAALg/93V8eVAk3Qw/s1600/Hutcheon.png" imageanchor="1" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" height="640" src="http://2.bp.blogspot.com/_PnCPTb2jz6w/TPJX8M16PLI/AAAAAAAAALg/93V8eVAk3Qw/s640/Hutcheon.png" width="464" /></a></div><div>It is interesting to follow Hutcheon's reasoning when he compares these two sections 46 years ago:</div><div><br />
</div><i><b>Wall to the left</b> is representative of a number of current designs that have been used quite extensively in recent buildings. It is of a basic form consisting of 8-in. back-up and 4-in. facing, in this case stone, which has been widely used in Canada over the past 50 years or more. Insulation is now commonly added to the inside, and may take several forms including mineral wool between strapping or foamed plastic serving also as plaster base. Full mortar backing, which usually requires a very wet mortar, is commonly used behind the stone.</i><br />
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</span></span></div><i>(...) Reference to the winter temperature gradients for Wall to the left will show that all material outside the insulation will fall below freezing. (...) Rain penetration through cracks, occurring as a result of temperature movement in the exterior cladding, can also allow the entry of water and the wetting of the wall.</i></div><div><i><br />
</i></div><i>A dramatic difference in temperature conditions and their attendant dimensional changes can be effected by moving the location of the insulation, see <b>Wall to the right</b>. The main wythe and all the parts of the structure in contact with it are subjected to a much smaller range of temperatures. The possibility of disruptive dimensional changes arising from temperature effects is greatly reduced for all but the exterior cladding and, as will be discussed, these can readily be accommodated. </i><i>The window frame, now bedded in or fastened to the warm interior wythe, is relieved of the substantial edge-cooling effect of the former arrangement. Advantage can be taken of the inside metal sill to collect and conduct heat to the frame, and a thermal break may be incorporated on the outside to minimize the loss of heat in winter.</i></div><div><i><br />
</i></div><div><i>(...) </i><i>The exterior cladding can be arranged as shown for Wall to the right in the form of an open rain screen. It may be set out to form an air space and supported by ledger angles and ties as before. The air space, being heavily vented by suitably designed open joints at both horizontal and vertical intervals, will at all times follow closely the outside air pressure so that the rain screen is substantially relieved of wind pressure differences. This not only removes the major force causing rain to penetrate the cladding, but also eliminates the wind loads on it.</i></div><div><i><br />
</i></div><div>Isn't it amazing? We are still - 46 years later - teaching this exact lesson to new generations of equally astonished architects. Even worse, we still see in 2010 a number of projects with wall sections similar to the left detail instead of to the right one. Lstibureck goes one step further in his paper to discuss the preferred position not just of the thermal barrier, but of the four control barriers as he calls them: rain, air, vapor and thermal. The details are clear in his article. I will summarize here one of the conclussions because it is of great help for us to do a good detail of any building envelope - be it a wall, a roof or a slab in contact with the earth.</div><div class="separator" style="clear: both; text-align: center;"><a href="http://2.bp.blogspot.com/_PnCPTb2jz6w/TPKGOqa6VBI/AAAAAAAAALk/1Srat7p5gso/s1600/roof+slab.png" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="216" src="http://2.bp.blogspot.com/_PnCPTb2jz6w/TPKGOqa6VBI/AAAAAAAAALk/1Srat7p5gso/s640/roof+slab.png" width="640" /></a></div><div><br />
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</div><div>Lstiburek describes first the roof adequate build-up (image above to the left) and then the slab in contact with the earth (image to the right), to find out a striking similarity between those two and with a perfect vertical wall: </div><div><i><br />
</i></div><div><i>The perfect roof is sometime referred to as an “inverted roof” since the rainwater control layer is under the insulation and ballast (i.e. roof cladding). Personally I don’t view it as inverted. Those other folks got it wrong by locating the membrane exposed on the top of the insulation—it is they that are inverted. </i><i>The perfect slab has a stone layer that separates it from the earth that acts as a capillary break and a ground water control layer. This stone layer should be drained and vented to the atmosphere— just as you would drain and vent a wall cladding.</i></div><div><i><br />
</i></div><i>Notice that in the perfect roof assembly the critical control layer - the membrane for rainwater control, air control and vapor control is located under the thermal insulation layer and the stone ballast (i.e. “roof cladding”) so that it is protected from the principle damage functions of water, heat and ultra violet radiation.</i><br />
<div class="separator" style="clear: both; text-align: center;"><a href="http://3.bp.blogspot.com/_PnCPTb2jz6w/TPKIIzfmgMI/AAAAAAAAALo/Gbptko7wWB8/s1600/roof+meets+wall.jpg" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="221" src="http://3.bp.blogspot.com/_PnCPTb2jz6w/TPKIIzfmgMI/AAAAAAAAALo/Gbptko7wWB8/s400/roof+meets+wall.jpg" width="400" /></a></div><div><i>What happens where roofs meet walls?. The classic roof-wall intersection is presented in the figure to the left. Notice that the control layer for rain on the roof is connected to the control layer for rain on the wall, the control layer for air on the roof is connected to the control layer for air on the wall . . . and so it goes. Beautiful. And when it is not so…ugly.</i></div><i><br />
In a beautiful bit of elegance and symmetry <span class="Apple-style-span" style="text-decoration: underline;">if you lie the perfect wall down you get the perfect roof and then when you flip it the other way you get the perfect slab.</span> The physics of walls, roofs and slabs are pretty much the same—no surprise. </i><br />
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</i></div><div class="separator" style="clear: both; text-align: center;"><a href="http://1.bp.blogspot.com/_PnCPTb2jz6w/TPKJ_NUiSuI/AAAAAAAAALs/eJ6EONvYS1w/s1600/wall-roof-slab.jpg" imageanchor="1" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" height="260" src="http://1.bp.blogspot.com/_PnCPTb2jz6w/TPKJ_NUiSuI/AAAAAAAAALs/eJ6EONvYS1w/s400/wall-roof-slab.jpg" width="400" /></a></div><div>This insight was shown into a whole generation of practitioners by the good building envelope specialists since back in the sixties. Where? Our friend Lstiburek is proud to have got it at the University around the eighties - he is a mechanical engineer. Others can not be that lucky: I found this piece of information by myself after finishing my architectural studies. It doesn't matter when - what matters is that, once you get it, you should never again forget it. Articles as clear as this one remind us this lesson. And there are many others at the <a href="http://www.buildingscience.com/">Webpage</a>... so please, go there and have a look, for your own benefit.</div>Ignacio Fernández Sollahttp://www.blogger.com/profile/03918193520738485621noreply@blogger.com13tag:blogger.com,1999:blog-1298203288964657974.post-44475115884702883042010-11-26T18:50:00.007+01:002010-11-26T22:27:27.963+01:00Large glass installation: miracles of vacuum liftingThe cladding world has gone mad. Facade units get bigger and bigger every year. Glass and panel dimensions are exceeding any reasonable measure. Who are to be blamed for it? Architects are partly responsible, for sure. The last gossip says Foster + Partners are designing a big company HQ in the Pacific coast with 15m long insulated glass units. Seismic movements in the region don't seem to refrain the architects from trying the impossible once again... <br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/_PnCPTb2jz6w/TOkEsZlQoeI/AAAAAAAAAKw/GL0L9H1qkMg/s1600/Henze-Glas+giant+DGU+before+Glasstec.jpg" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="218" src="http://3.bp.blogspot.com/_PnCPTb2jz6w/TOkEsZlQoeI/AAAAAAAAAKw/GL0L9H1qkMg/s640/Henze-Glas+giant+DGU+before+Glasstec.jpg" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span class="Apple-style-span" style="font-family: Times, 'Times New Roman', serif;"><i><span class="Apple-style-span" style="font-size: xx-small;">Henze-Glas DGU in the factory, before shipping to Glasstec 2010. 35 chaps are sitting on top of the 18m long glass unit</span></i></span></td></tr>
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<tr><td style="text-align: center;"><a href="http://4.bp.blogspot.com/_PnCPTb2jz6w/TOk-8YzO8sI/AAAAAAAAAK8/tertTXRnysI/s1600/Henze+Glas+piece+at+Glasstec+2010.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="400" src="http://4.bp.blogspot.com/_PnCPTb2jz6w/TOk-8YzO8sI/AAAAAAAAAK8/tertTXRnysI/s400/Henze+Glas+piece+at+Glasstec+2010.png" width="277" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span class="Apple-style-span" style="font-size: xx-small;"><span class="Apple-style-span" style="font-family: Times, 'Times New Roman', serif;"><i>The monster DGU unit as shown at Glasstec 2010</i></span></span></td></tr>
</tbody></table>But industry has also entered the race with pleasure. The 'jumbo size' glass, that is, the maximum dimensions of a glass sheet, was 6,000 x 3,210mm up to 2007. Since then a new jumbo size appeared: 9,000 x 3,210mm. <a href="http://glassbel.com/products/bigsize/">Double glass units of 7,500 x 3,200mm</a> or even 9,000 x 3200mm are now commercially avilable. Visitors at the last Glasstec Düsseldorf in October 2010 could see a huge insulated glass panel of 18,000 x 3,300mm! It had three layers of 10mm and weighed 4,5 tons. The producer was the large-dimensions glass specialist <a href="http://www.henzeglas.de/">Henze-Glas</a> from Hörden, Germany.<br />
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The Henze-Glas guys usually take care of the fabrication and supply of their glass units to jobsite, all in one, since large dimensions are not easy to handle. But the tricky question is: how can a facade contractor install glass or metal panel units around 10m long in a facade? This is the issue we are going to discuss in this post.<br />
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<div style="margin: 0px;">Mankind has been aware of the power of air pressure since Otto von Guericke’s demonstration of the <a href="http://en.wikipedia.org/wiki/Magdeburg_hemispheres">Magdeburg hemisferes</a> in 1656, when 16 horses were unable to separate two hemispheres which had been pumped free of oxygen. Boyle and Hooke, two good old names of physics, worked together to design and build an improved air pump. Their work was the origin of the Boyle's law: the volume of a gas body is inversely proportional to its pressure.<br />
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<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/_PnCPTb2jz6w/TO_PPI-4mTI/AAAAAAAAALA/G6wuddenliw/s1600/early+Wood%2527s+Powr+Grip+cups.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="252" src="http://1.bp.blogspot.com/_PnCPTb2jz6w/TO_PPI-4mTI/AAAAAAAAALA/G6wuddenliw/s640/early+Wood%2527s+Powr+Grip+cups.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><i><span class="Apple-style-span" style="font-family: Times, 'Times New Roman', serif;"><span class="Apple-style-span" style="font-size: x-small;">Early Wood's Powr Grip cups, beginning of 1960's</span></span></i></td></tr>
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</div>It wasn’t until the 1960s that air pressure power started to be used with vacuum lifting equipment for transporting and installing glass panels at construction sites. One of the founders of the guild was Howard Wood, who in 1961 designed and built the first <a href="http://www.powrgrip.com/cgi-bin/powrgrip/index.html">Wood's Powr-Grip</a> Valve Grinder. The tool consisted of a small, spring-action vacuum pump mounted in a wooden handle, opposite a rubber suction cup which attached to the flat surface of an engine valve. The demand for the unique little lifting tool grew, and a glazier friend from Wood's suggested that he develop a vacuum cup for handling glass. With support from friends, Howard began manufacturing vacuum cups for glass handling in 1963, and obtained a patent for his design in March 1966.<br />
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<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/_PnCPTb2jz6w/TO_Xd_zbIEI/AAAAAAAAALE/mrH067vyOyk/s1600/Hydraulica+2000-1.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="391" src="http://1.bp.blogspot.com/_PnCPTb2jz6w/TO_Xd_zbIEI/AAAAAAAAALE/mrH067vyOyk/s640/Hydraulica+2000-1.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><i><span class="Apple-style-span" style="font-family: Times, 'Times New Roman', serif;"><span class="Apple-style-span" style="font-size: x-small;">Hydraulica 2000 vacuum lifter</span></span></i></td></tr>
</tbody></table>Vacuum cups were soon attached to cranes or lifting devices, and soon a new machine came into play: vacuum lifters. The generally smooth and gas-tight surface of glass means vacuum lifting devices are just right for the job. That is also the case with metal panels. These days even stone and prefab concrete panels are lifted and moved using air suckers.<br />
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<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/_PnCPTb2jz6w/TO_ld0y7ucI/AAAAAAAAALI/xhSWd5LXjSg/s1600/rotate-glass1.jpg" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="400" src="http://1.bp.blogspot.com/_PnCPTb2jz6w/TO_ld0y7ucI/AAAAAAAAALI/xhSWd5LXjSg/s400/rotate-glass1.jpg" width="267" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span class="Apple-style-span" style="font-family: Times, 'Times New Roman', serif;"><span class="Apple-style-span" style="font-size: x-small;"><i>Vacuum lift atached to a crane from Anver</i></span></span></td></tr>
</tbody></table><a href="http://www.wirth-gmbh.com/en/vacuum-lifter.html">Wirth GmbH</a> is a German company that builds applications for vacuum lifting. The first version of their Oktopus lifter appeared in 1992. With devices like that installing large-format roofing, ceiling and facade panels made of sandwich, profiled sheets and glass has become much easier. Today's vacuum lifting equipment is based on individual suction cups attached to thin structural elements hung from a crane. These systems allow for the installation of vertical wall panels up to 12m long, or even horizontal roof panels up to 22m long.<br />
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The lifting devices can be hung from a crane, attached to a forklift, to a truck-mounted crane or to an elevated working platform - also known as cherry picker. Several hydraulic functions integrated into the vacuum lifters allow panels to swing up and down, be raised and lowered, twist left and right, or move forward and backward horizontally.<br />
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One of the best options is to use a vacuum lifter attached to a minicrane, also called a spider crane. Two European companies are well-known builders of minicranes: <a href="http://www.unic-cranes.co.uk/">Unic Cranes</a> from Scotland and <a href="http://www.riebsamen.de/english/produkte/glasboy.html">Riebsamen</a> from Germany, the latter being better known for their brand Glasboy. These minicranes can be used for mounting curtain wall units from the floor above, or for mounting glass in a skylight from the atrium below. The dimensions of a minicrane when its legs and arm are folded are really minimal, allowing the smallest minicranes to be lifted inside an elevator.<br />
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<tr><td style="text-align: center;"><a href="http://4.bp.blogspot.com/_PnCPTb2jz6w/TO_mSXwskKI/AAAAAAAAALM/m3X2c0ch3tU/s1600/glasboss_frei_460.jpg" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="396" src="http://4.bp.blogspot.com/_PnCPTb2jz6w/TO_mSXwskKI/AAAAAAAAALM/m3X2c0ch3tU/s400/glasboss_frei_460.jpg" width="400" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span class="Apple-style-span" style="font-family: Times, 'Times New Roman', serif;"><span class="Apple-style-span" style="font-size: x-small;"><i>Minicrane Glasboy Frey 860 from Riebsamen</i></span></span></td></tr>
</tbody></table>Some special devices can solve typical installation problems. One of them is the presence of overhangs in high level installation works. If a cantilevered slab prevents cranes from lowering their load flush with the envelope, an overhang beam provides an ingenious way of overcoming the problem. The <a href="http://www.ggrglass.co.uk/product.php?action=showproduct&PID=150">Libro 500 overhang beam</a> for example provides a reach from suspension point to pad extension that allows glazing under overhangs up to a depth of 1,750mm.<br />
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</div><div>All the options of cranes, minicranes and vacuum lifting devices can be checked (and hired, if you need them) at the <a href="http://www.ggrglass.co.uk/index.php">UK webpage of GGR Group</a>, a must see for those with a lifting problem to solve. If your site is in the US, then go visit the founding fathers, the guys of <a href="http://www.powrgrip.com/cgi-bin/powrgrip/index.html">Wood's Powr Grip</a>. If your doubts are more general or you want to have an overview of the crane and lifting world, have a look at <a href="http://www.vertikal.net/">Vertikal</a> magazine.<br />
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<span class="Apple-style-span" style="font-family: Arial, Helvetica, sans-serif; font-size: 10px;"></span>Now, let us enter a slightly tougher issue. Which lifting device do I need for my load? How many suction cups are required considering the glass dimensions? Is suction lifting really safe? Depending on the application and the device, the load bearing capacity of a vacuum lifter varies between 250 kg and 1,000 kg. Vacuum lifting devices suitable for construction sites must be battery powered and therefore completely self-sufficient. A safety system inside the device constantly monitors the condition of the vacuum circuit and the batteries. Optical and acoustic warning signals give early indication of deviations from the normal conditions. A reserve vacuum system maintains load bearing capacities even in the event of a loss of power, so that there is enough time to safely deposit the load once an alarm goes off.<br />
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<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/_PnCPTb2jz6w/TO_s0lgTMlI/AAAAAAAAALQ/xKTShQyOM-w/s1600/crane+%252B+overhang.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="233" src="http://2.bp.blogspot.com/_PnCPTb2jz6w/TO_s0lgTMlI/AAAAAAAAALQ/xKTShQyOM-w/s640/crane+%252B+overhang.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span class="Apple-style-span" style="font-family: Times, 'Times New Roman', serif;"><span class="Apple-style-span" style="font-size: x-small;"><i>Robotic (left) and Libro 500 overhang crane lifts</i></span></span></td></tr>
</tbody></table>European norm EN 13155 defines how to verify the load bearing capacity of vacuum lifting equipment. Load bearing parts are to be checked at three times the nominal load bearing capacity of the device. Vacuum lifters must be able to hold a load, in all positions at the end of the vacuum range, of at least two times the nominal load bearing capacity of the device. The combination of vacuum lifting device and suctioned load must, obviously, not exceed the load bearing capacity of the lifting equipment (crane / forklift / working platform). If you are interested in the same topic from the US, your document should be ASME Standard B30.20, addressing vacuum lifting and general materials handling products.<br />
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The load bearing capacity of the suction cups depends mainly on the following four factors: a) Size of the suction cups; b) Pressure difference between the level of vacuum in the suction cup and the ambient pressure; c) Load direction (vertical, parallel or sloped to the suction cup surface); and d) Surface properties and porosity of the suctioned material.</div><div class="bodytext"><br />
</div><div class="bodytext">As a rule of thumb, a vacuum lifter used at a height of 1000m admits 10% less weight than the same device at sea level. The load direction is even more critical. If the load to be lifted is picked and released in a horizontal position, the maximum load capacity will be two times higher than if the load has be hold in vertical. Finally, the suction cup diametre defines the load bearing capacity of the system. The chart below, taken from Wirth Webpage, shows the relationship between suction cup diametre and load bearing at sea level for both horizontal (blue line) and vertical (red line) load directions.</div><div class="separator" style="clear: both; text-align: center;"><a href="http://3.bp.blogspot.com/_PnCPTb2jz6w/TOkUApkkk-I/AAAAAAAAAK4/q2sXXC_0xX8/s1600/804af06306.png" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="476" src="http://3.bp.blogspot.com/_PnCPTb2jz6w/TOkUApkkk-I/AAAAAAAAAK4/q2sXXC_0xX8/s640/804af06306.png" width="640" /></a></div><div class="bodytext"><br />
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We started this post talking about large glass units. The vacuum lifters you can find in the market have a maximum load bearing capacity of 1 metric ton at best. What if your glass is really large - and heavy? No problem, there is always a German wizard with a solution for that - regardless the names they give to their inventions. Bystronic Glass has built the <a href="http://www.glassonweb.com/news/index/7242/">world's largest glass vacuum lifter</a> up to now: the Glasmaxilift 5000 is able to handle glass lites up to 15 meters in length and 5 metric tons using just air pressure. You got it. And Foster + Partners will have their huge glass installed as well.<br />
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</div></div></div>Ignacio Fernández Sollahttp://www.blogger.com/profile/03918193520738485621noreply@blogger.com18tag:blogger.com,1999:blog-1298203288964657974.post-21322312800126962352010-11-14T09:09:00.208+01:002012-05-13T23:44:07.464+02:00Will transparent polymers kill glass?<div style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;">
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A silent revolution is taking place these days. Due to a number of reasons, the glass position as the one and only transparent filling for curtain walls is being threatened. Who is the new kid on the block? Well, it has been around for a while, but it has grown bigger now: transparent recyclable polymers, commonly called thermoplastics.<br />
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<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/_PnCPTb2jz6w/TN_hYYbnbEI/AAAAAAAAAKM/dZhtgNTsqNU/s1600/Tokio+glass+cantilever.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="426" src="http://3.bp.blogspot.com/_PnCPTb2jz6w/TN_hYYbnbEI/AAAAAAAAAKM/dZhtgNTsqNU/s640/Tokio+glass+cantilever.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><i><span class="Apple-style-span" style="font-family: Times, 'Times New Roman', serif;"><span class="Apple-style-span" style="font-size: x-small;">Tokyo glass and acrylic cantilevered structure, Dewhurst Macfarlane</span></span></i></td></tr>
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The attack of the polymers has already started, in the way barbarians entered the Roman empire: as an alliance. If you need a good bullet resistant glass you will end up in a laminate called glass-clad polycarbonate. Beware: the higher the bullet resistance requirements, the less glass there will be in the laminate. If you are after a blast-resistant curtain wall, the options are heavy PVB laminated glass (1.52mm or more of polyvinyl butiral layers) or glass combined with an ionoplastic interlayer as SetryGlas, in widths of 2.28mm or more. If you want to have overhead glazing or horizontal glass with live loads, there you will find the plastic companions again. Structural glass is in fashion, and you may want to achieve all-glass, non metal-supported transparent structures. When you do that, most of the time it's due to the help of polycarbonate sheets glued to the glass with transparent polyurethane interlayers.<br />
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<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/_PnCPTb2jz6w/TN_h7PbjVwI/AAAAAAAAAKQ/UeXjc7XbQnc/s1600/Tokyo+glass+cantilever+details.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="260" src="http://2.bp.blogspot.com/_PnCPTb2jz6w/TN_h7PbjVwI/AAAAAAAAAKQ/UeXjc7XbQnc/s640/Tokyo+glass+cantilever+details.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><i><span class="Apple-style-span" style="font-size: x-small;"><span class="Apple-style-span" style="font-family: Times, 'Times New Roman', serif;"><span class="Apple-style-span" style="font-size: x-small;">Tokyo International Forum, glass canopy details. PMMA was not required structurally but it was added as a safety measure against typhoons and earthquake</span><span class="Apple-style-span" style="font-size: x-small;">s.</span></span></span></i></td> </tr>
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This was the situation up to now. Glass is still in complete command if we want to clad a facade with a transparent, low U-value, durable and non combustible material. A curtain wall is still synonym for a glass curtain wall. But things are starting to change, and the big polymers suppliers have focused their attention onto the new frontier: to introduce Transparent Composite Facades (TCF) in lieu of Glass Curtain Walls (GCW).<br />
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I have taken the TCF name from a PhD dissertation in the University of Michigan, submitted by Kyoung-Hee Kim in 2009, and advised by Professor Harry Giles. The title is <a href="http://deepblue.lib.umich.edu/handle/2027.42/64749">Structural evaluation and life cycle assessment of a Transparent Composite Facade system</a>. I have also got ideas for this post from a presentation at the last Glasstec conference in Sept 2010: New materials for transparent constructions, by Eckhardt and Stahl.<br /><br /><table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em;"><tbody>
<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/_PnCPTb2jz6w/TN_jK0IUGdI/AAAAAAAAAKU/MqAYCJZ3I9o/s1600/Prism+cultural+centre+West+Hollywood.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="206" src="http://3.bp.blogspot.com/_PnCPTb2jz6w/TN_jK0IUGdI/AAAAAAAAAKU/MqAYCJZ3I9o/s640/Prism+cultural+centre+West+Hollywood.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><i><span class="Apple-style-span" style="font-size: x-small;"><span class="Apple-style-span" style="font-family: Times, 'Times New Roman', serif;">Prism Cultural Centre in West Hollywood, California by PATTERN Architects. Translucent facade in resin-based composite polycarbonate. 3Form, an advanced material fabrication company specializing on resin-based composites, has collaborated on the facade solution.</span></span></i></td> </tr>
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The contenders to take the place of glass in curtain walls are four thermoplastics: <i>polycarbonate</i> (PC), <i>polymethylmethacrylate</i> (PMMA or acrylic), <i>polyethylene terephthalate</i> (PET or nylon) and <i>polypropylene</i> (PP). PET and PP are still lagging behind in the race, mostly because of their low stiffness and low ultimate strength. PET and PP have a Young's modulus 1/7 and 1/2 that of polycarbonate and acrylic, and their ultimate strenght is 1/3 that of polycarbonate and acrylic. The main advantages of polycarbonate and acrylic, on the other hand, is that they are 20 times less brittle than glass and their ultimate streght can be two times higher than glass (see data on the table below). So, we will focus on polycarbonate and PMMA / acrylic from now on.<br />
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<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/_PnCPTb2jz6w/TN_kVcQFGJI/AAAAAAAAAKY/ys8pDZP--Vs/s1600/Thermoplastics+%2526+glass+data.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="256" src="http://1.bp.blogspot.com/_PnCPTb2jz6w/TN_kVcQFGJI/AAAAAAAAAKY/ys8pDZP--Vs/s640/Thermoplastics+%2526+glass+data.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><i><span class="Apple-style-span" style="font-size: x-small;"><span class="Apple-style-span" style="font-family: Times, 'Times New Roman', serif;">From 'Materials and design' by Ashby and Johnson, plus www.matweb.com</span></span></i></td></tr>
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Some may say these two materials have been around for too long to worry about them now. That is true, but doesn't tell the whole story. Let's call them by their best-known brands: polycarbonate is better known as Lexan, Makrolon or Danpalon. PMMA / acrylic is sold under the brands Plexiglas, Lucite or Perspex. Polycarbonate, either in solid or in multilayered sheets, has found a safe place in architecture as a translucent wall cladding, not transparent. A great example is the Laban Dance Centre in Southern London, a proyect by the Swiss architects Herzog & de Meuron with PC sheets supplied by <a href="http://www.rodeca.de/DE/A_fassade/01fassade_en.htm">Rodeca in Germany</a>.<br />
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<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/_PnCPTb2jz6w/TN_DWMfXpmI/AAAAAAAAAJg/SfWeJvz-FbA/s1600/Laban+Centre+polycarbonate.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="222" src="http://1.bp.blogspot.com/_PnCPTb2jz6w/TN_DWMfXpmI/AAAAAAAAAJg/SfWeJvz-FbA/s640/Laban+Centre+polycarbonate.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span class="Apple-style-span" style="font-family: Times, 'Times New Roman', serif;"><i><span class="Apple-style-span" style="font-size: x-small;">Laban Contemporary Dance Centre, London. Herzog & de Meuron architects</span></i></span></td></tr>
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The cladding on the Laban Centre has four layers with a U-value of 1.45 W/m2°K, better than a low-e double glass unit. But present multiwall polycarbonate sheets, only 60mm thick, have already reduced the <a href="http://www.rodeca.de/EN/aktuell_full.php?id=35">U-value to 0.85W/m2ºK</a>, in the range of a triple glass with argon and low-e coatings. Polycarbonate can also reduce reliance on secondary solar control; the panels used at the Laban Centre feature dimpled inner skins that diffuse the light. Concerns over the durability and UV resistance of polycarbonate have now been reduced thanks to new film protection technology. Manufacturers now guarantee that the polycarbonate will lose no more than 1% of its transparency over the first 10 years. All this is fine, but this is still a translucent wall, a cladding material for gyms, dance centres, swimming pools or industrial buildings.<br />
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<span style="color: black;"><span class="Apple-style-span" style="font-size: x-small;"><span class="Apple-style-span" style="font-family: Times, 'Times New Roman', serif;"><i>V-</i></span></span></span><span style="color: black;"><span class="Apple-style-span" style="font-size: x-small;"><span class="Apple-style-span" style="font-family: Times, 'Times New Roman', serif;"><i>profile</i></span></span></span><span style="color: black;"><span class="Apple-style-span" style="font-size: x-small;"><span class="Apple-style-span" style="font-family: Times, 'Times New Roman', serif;"><i> by </i></span></span></span><span style="color: black;"><span class="Apple-style-span" style="font-size: x-small;"><span class="Apple-style-span" style="font-family: Times, 'Times New Roman', serif;"><i>Rodeca</i></span></span></span><span style="color: black;"><span class="Apple-style-span" style="font-size: x-small;"><span class="Apple-style-span" style="font-family: Times, 'Times New Roman', serif;"><i>, a </i></span></span></span><span style="color: black;"><span class="Apple-style-span" style="font-size: x-small;"><span class="Apple-style-span" style="font-family: Times, 'Times New Roman', serif;"><i>mullion</i></span></span></span><span style="color: black;"><span class="Apple-style-span" style="font-size: x-small;"><span class="Apple-style-span" style="font-family: Times, 'Times New Roman', serif;"><i> in </i></span></span></span><span style="color: black;"><span class="Apple-style-span" style="font-size: x-small;"><span class="Apple-style-span" style="font-family: Times, 'Times New Roman', serif;"><i>extruded</i></span></span></span><span style="color: black;"><span class="Apple-style-span" style="font-size: x-small;"><span class="Apple-style-span" style="font-family: Times, 'Times New Roman', serif;"><i> </i></span></span></span><span style="color: black;"><span class="Apple-style-span" style="font-size: x-small;"><span class="Apple-style-span" style="font-family: Times, 'Times New Roman', serif;"><i>polycarbonate</i></span></span></span><span style="color: black;"><span class="Apple-style-span" style="font-size: x-small;"><span class="Apple-style-span" style="font-family: Times, 'Times New Roman', serif;"><i> </i></span></span></span></div>
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The next step for solid polycarbonate and acrylic is to become the transparent filling of a curtain wall, both in the fix elements and in the windows. A transparent composite facade (TCF) is well described by Kyoung-Hee Kim's dissertation as:<br />
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<i>A composite construction consisting of a polymer double skin with an inner composite core, configured to provide a stiffer, safer, energy efficient and lightweight alterative to a glass façade system. </i><br />
<i>This new 'glazing' system has spurred studies that evaluate the material performance of polymer and composites as a cladding material. The polymer skin has a sustainable characteristic due to its recyclability, which can help to reduce the environmental impact associated with raw material depletion and disposal.</i><br />
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Let's use an existing example to visualize the new TCF coming. <a href="http://www.kalwall.com/">Kalwall</a> is a well known US translucent facade and skylight system, whose filling material by the way is a thermo-set polymer reinforced with fiberglass, with modified properties regarding UV-resistance and reaction to fire. The basic panel comes in standard dimensions and is installed as a very simple curtain wall unit sistem.<br />
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<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/_PnCPTb2jz6w/TN_FABUj9DI/AAAAAAAAAJo/2dW3rgke_LE/s1600/City+%2526+Islington+College%252C+Kalwall.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="227" src="http://3.bp.blogspot.com/_PnCPTb2jz6w/TN_FABUj9DI/AAAAAAAAAJo/2dW3rgke_LE/s640/City+%2526+Islington+College%252C+Kalwall.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span class="Apple-style-span" style="font-family: Times, 'Times New Roman', serif;"><i><span class="Apple-style-span" style="font-size: x-small;">City & Islington College, London. Van Heyningen and Haward architects. Kalwall and glass facade.</span></i></span></td></tr>
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The best version of Kalwall, pushed by <a href="http://www.stoakes.co.uk/">Stoakes</a> (the UK distributor) to comply with EU directives, has really low U-values by using thermally broken profiles combined with aerogel insulation. Even without aerogels you can have a 100mm panel, filled with polycarbonate fibres, with a U-value of 0.83W/m2ºK and a solar factor of 0.15. But, alas, it's still translucent. Now, imagine you replace the fiberglass reinforced thermoset at both sides of the panel with a high resistant solid policarbonate sheet, and add some intermediate transparent sheets to improve its U-value and acoustic performance. The outcome would be something similar to Kalwall - with the same Japanese paper-like rectangular pattern - but wholly transparent, no glass required whatsoever. Stop imagining, this concept is already being developed somewhere in Europe.<br />
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If we move to PMMA / acrylic, a similar story is being written these days. The material can be easily molded to achieve fuzzy shapes at a cost which is only a fraction of glass. In solid state, acrylic sheets can be cut and mechanized using laser cut CNC machines to provide extrusion-like profiles. A great example is the facade of the <a href="http://www.whowithwhat.com/company/BuildingDetail.php?name=Reiss%20HQ,%20London">Reiss HQ building in London</a> by Squire and Partners architects, with a machined PMMA external skin, and lit with an LED system at the bottom of each floor level.<br />
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<a href="http://1.bp.blogspot.com/_PnCPTb2jz6w/TN_Gc8YFBvI/AAAAAAAAAJs/NHrJv4GJIlE/s1600/Reiss+store+facade+acrylic.png" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="235" src="http://1.bp.blogspot.com/_PnCPTb2jz6w/TN_Gc8YFBvI/AAAAAAAAAJs/NHrJv4GJIlE/s640/Reiss+store+facade+acrylic.png" width="640" /></a></div>
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<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/_PnCPTb2jz6w/TN_HOfxd6GI/AAAAAAAAAJw/K2KAq1cPEbw/s1600/Reiss+acrylic+facade+section.png" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="640" src="http://1.bp.blogspot.com/_PnCPTb2jz6w/TN_HOfxd6GI/AAAAAAAAAJw/K2KAq1cPEbw/s640/Reiss+acrylic+facade+section.png" width="512" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span class="Apple-style-span" style="font-family: Times, 'Times New Roman', serif;"><i><span class="Apple-style-span" style="font-size: x-small;">Reiss London. Double skin facade with acrylic and glass. </span></i></span></td></tr>
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<tr><td style="text-align: center;"><a href="http://4.bp.blogspot.com/_PnCPTb2jz6w/TN_HvsPL36I/AAAAAAAAAJ0/fhJOpTcBQA0/s1600/Reiss+acrylic+milling+process+and+complete+panel.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="236" src="http://4.bp.blogspot.com/_PnCPTb2jz6w/TN_HvsPL36I/AAAAAAAAAJ0/fhJOpTcBQA0/s640/Reiss+acrylic+milling+process+and+complete+panel.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span class="Apple-style-span" style="font-family: Times, 'Times New Roman', serif;"><i><span class="Apple-style-span" style="font-size: x-small;">Reiss London. Acrylic milling process and finished facade panel.</span></i></span></td></tr>
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<a href="http://corporate.evonik.com/en/chemicals/products/75_years_of_plexiglas/pages/default.aspx">Evonik Röhm</a>, the company that owns the Plexiglas brand, was founded by Mr Röhm, the inventor of PMMA in 1933. After almost 40 years, the Olympic stadium in Munich by Frei Otto is still a forward-looking piece of architecture. The complex grid of steel cables was clad with a solid, tinted Plexiglas sheet to provide shelter against the summer sun rays. Need versatility? The monolithic thickness of PMMA is 200mm in a dimension of 3 x 8m - larger than glass, and you can even weld acrylic with hidden joints for bigger units. In the extrusion process you can obtain 25mm thickness, a width of 2m and no limit with length.<br />
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<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/_PnCPTb2jz6w/TN_KtOZ8xQI/AAAAAAAAAJ4/JUYI0OnVgkU/s1600/Olympic+Stadium+Munich.+Frei+Otto.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="202" src="http://1.bp.blogspot.com/_PnCPTb2jz6w/TN_KtOZ8xQI/AAAAAAAAAJ4/JUYI0OnVgkU/s640/Olympic+Stadium+Munich.+Frei+Otto.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span class="Apple-style-span" style="font-family: Times, 'Times New Roman', serif;"><i><span class="Apple-style-span" style="font-size: x-small;">Olympic Stadium, Munich 1972. Frei Otto and Günther Behnish.</span></i></span></td></tr>
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Curving a polymer is easy, but equally so is molding. Transparent facades as the one at the Liquid Wall in Berlin, the flagship store of Raab Karcher, would be a nightmare in glass, but are feasible in acrylic. Home Couture Berlin is a showroom for tiles and spa accessories. The store provides an ideal presentation platform for Raab Karcher and its joint-venture partners from the premium tile and bathroom fittings sector. The store functions as an elongated shop window for passers-by.<br />
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<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/_PnCPTb2jz6w/TN_L-bG7GBI/AAAAAAAAAJ8/jGOhCyVS_nM/s1600/Home+Couture+Berlin.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="265" src="http://2.bp.blogspot.com/_PnCPTb2jz6w/TN_L-bG7GBI/AAAAAAAAAJ8/jGOhCyVS_nM/s400/Home+Couture+Berlin.png" width="400" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><i><span class="Apple-style-span" style="font-family: Times, 'Times New Roman', serif;"><span class="Apple-style-span" style="font-size: x-small;">Raab Karcher flagship store, Berlin</span></span></i></td></tr>
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The ‘liquid wall’ installation of milled Plexiglas appears as a vertical wall of water and serves as an eye-catcher in the Ku'Damm facade. The distorting lens makes the illuminated back wall oscillate as you wander past it. The shop window has been made after a 50mm Plexiglas sheet milled, formed and polished to get convex and concave surfaces. This form creates an effect of a moving room while walking by the window, as if the inside were a swimming pool.<br />
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If you need more inspiration, have a look at these four polymer materials suppliers: <a href="http://www.3-form.com/">3form</a>, <a href="http://www.e-panelite.com/">Panelite</a>, <a href="http://www.Lightblocks.com/index.php">Lightblocks</a> and <a href="http://www.krystaclear.com/">Krystaclear</a>. These are all US-based companies at the verge of another revolution: they are not just suppliers, but also fabricators, engineers, materials researchers and high-end designers. They are in the front of the 'design to manufacture' concept that is changing the way materials are used. And they are all based in polymers.<br />
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When you can't win your enemies, join them. Another interesting product is <a href="http://www.glasstec.de/cgi-bin/md_glasstec/custom/pub/content.cgi?lang=2&oid=8385&ticket=g_u_e_s_t&ca_page=en%2Fspezialglas-laesst-pflanzen-wieder-wachsen.php">Gewe-composite</a> by the German glass supplier Schollglas. This laminated safety glass made with two sheets of glass and an intermediate 2mm polymeric membrane, can replace thicker glass-PVB laminates, is very easy to cold bend and does not stop UV radiation, thus making it very appropriate for winter gardens. The <a href="http://www.architekturzeitung.eu/innovation/fassade-fenster/315-schollglas-gewe-composite.html">Amazonienhaus botanical greenhouse</a> in Stuttgart is a good example of high UV-transmission, low-e coating composite transparent cladding. Another striking use of this composite in a bent application - non heat mold required - is the Mobile Formula 1 Event Centre for McLaren in the UK. The cold bent composite here integrates metal sheets and comes with a highly selective coating.<br />
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<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/_PnCPTb2jz6w/TN_NB5XptrI/AAAAAAAAAKA/kE3a9A_PVEs/s1600/Amazonienhaus+Stuttgart.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="238" src="http://3.bp.blogspot.com/_PnCPTb2jz6w/TN_NB5XptrI/AAAAAAAAAKA/kE3a9A_PVEs/s640/Amazonienhaus+Stuttgart.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><i><span class="Apple-style-span" style="font-family: Times, 'Times New Roman', serif;"><span class="Apple-style-span" style="font-size: x-small;">Amazonienhaus Stuttgart. Glass laminated panels with high UV transmission from Schollglas</span></span></i></td></tr>
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<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/_PnCPTb2jz6w/TN_NXaQQftI/AAAAAAAAAKE/WYTfv09-oTw/s1600/Gewe-composite+from+Schollglas.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="192" src="http://3.bp.blogspot.com/_PnCPTb2jz6w/TN_NXaQQftI/AAAAAAAAAKE/WYTfv09-oTw/s640/Gewe-composite+from+Schollglas.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><i><span class="Apple-style-span" style="font-family: Times, 'Times New Roman', serif;"><span class="Apple-style-span" style="font-size: x-small;">Gewe-composite from Schollglas</span></span></i></td></tr>
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There are still issues to solve and improve with thermoplastics before they can replace glass in curtain walls. Even if their mechanical properties are OK in general (impact resistance being great in particular) long term creep deformation is a clear disadvantage. The elastic modulus of extruded polycarbonate, for example, can be reduced to 40% after 1000 hours of constant loading. Regarding durability, polymers and acrylics offer a lower durability and weatherability under outside exposure compared to glass. Coated protections against UV have improved this, but there is still a way to go. The yelowness index (YI) measures discoloration levels under UV exposure, and values above YI-8 are not recommended for external use.<br />
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Another issue that must be integrated in the design is the thermal movement of plastics. The coefficient of thermal expansion of both polycarbonate and PMMA is 6 to 7 times greater than that of glass. Beware of the expansion pockets and frame movements! Abrasion resistance of plastics has improved with external coatings, but its value is still 2 to 4 times lower than that of glass. The biggest issue with plastics as external facade elements is probably their flammability or fire reaction. On one side, PC, PMMA and glass all conform to the flammability requirements of the ASTM codes. However, full compliance with the International Building Code (IBC) has to be checked case by case. The IBC limits the installation of plastic glazing to a maximum area of 50% of a building facade.<br />
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<a href="http://1.bp.blogspot.com/_PnCPTb2jz6w/TN_ORgfFHOI/AAAAAAAAAKI/FBrR8op_QPY/s1600/Polymers+and+glass+comparison.png" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="624" src="http://1.bp.blogspot.com/_PnCPTb2jz6w/TN_ORgfFHOI/AAAAAAAAAKI/FBrR8op_QPY/s640/Polymers+and+glass+comparison.png" width="640" /></a></div>
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It is interesting to note that the U-value of a single layer of 6mm of transparent glass, polycarbonate or acrylic is practically the same: between 5,2 and 5,8W/m2ºK (glass being the highest). We get a similar result with g-value and light transmittance: uncoated glass and polycarbonate transmit the same amount of solar and visible radiation, while acrylic is slightly more transparent in both cases. But when we introduce selective coatings, glass performs much better than plastics in energy and visible light terms. Up to now, though.<br />
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Nobody knows the end of this story. Will new recyclable polymers completely replace glass as a transparent filling for curtain walls? It seems uncertain, but at least I would vote for a future co-habitation of both materials. If I had money to invest in the stock market, I would buy plastic shares rather than Saint Gobain ones. Well, don't follow my advice too quickly: Saint Gobain is investing in plastics right now, so think twice...Ignacio Fernández Sollahttp://www.blogger.com/profile/03918193520738485621noreply@blogger.com56tag:blogger.com,1999:blog-1298203288964657974.post-50714852944317118202010-11-08T16:43:00.123+01:002010-11-10T23:32:32.820+01:00Central Saint Giles: Piano goes to London<div class="MsoNormal" style="margin: 0cm 0cm 0pt;">Central Saint Giles, a London commercial and housing scheme designed by Renzo Piano, has been attracting attention ever since its glazed ceramic facades in tiles of red, orange, yellow, green and grey began to appear back in 2009. Now, with the complex finished after Spring 2010 and starting to be occupied, it is time to review its facade design and construction. </div><div><div style="border-bottom: medium none; border-left: medium none; border-right: medium none; border-top: medium none;"><div style="border-bottom: medium none; border-left: medium none; border-right: medium none; border-top: medium none;"><div style="border-bottom: medium none; border-left: medium none; border-right: medium none; border-top: medium none;"><br />
</div><div style="border-bottom: medium none; border-left: medium none; border-right: medium none; border-top: medium none;"><a href="http://4.bp.blogspot.com/_PnCPTb2jz6w/TNgK_uBD8II/AAAAAAAAAIs/zeyMLswGRF0/s1600/Central+St+Giles+at+dawn.jpg" imageanchor="1" style="clear: left; cssfloat: left; cssfloat: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="352" px="true" src="http://4.bp.blogspot.com/_PnCPTb2jz6w/TNgK_uBD8II/AAAAAAAAAIs/zeyMLswGRF0/s640/Central+St+Giles+at+dawn.jpg" width="640" /></a>Renzo Piano is a master for many of us. This building, nevertheless, has not attracted unanimous praise as usual. I think the reason is the difficulty underlying the task: difficulty because of the site, the density, the scale and the neighbourhood. Through this post I hope to present the lesson Piano has given to all of us: a lesson of working under difficult conditions and still come up with a victory. This may not be a victory for a building as a piece in itself, but a victory for a building that improves the city and its inhabitants. Good enough to me...</div><div style="border-bottom: medium none; border-left: medium none; border-right: medium none; border-top: medium none;"><br />
</div></div></div></div><div></div><div><div class="separator" style="border-bottom: medium none; border-left: medium none; border-right: medium none; border-top: medium none; clear: both; text-align: center;"><a href="http://4.bp.blogspot.com/_PnCPTb2jz6w/TNgOBzlokII/AAAAAAAAAIw/HQ42bJ-9X10/s1600/Central+St+Giles+concept+plan.png" imageanchor="1" style="clear: left; cssfloat: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="300" px="true" src="http://4.bp.blogspot.com/_PnCPTb2jz6w/TNgOBzlokII/AAAAAAAAAIw/HQ42bJ-9X10/s400/Central+St+Giles+concept+plan.png" width="400" /></a></div><div style="border-bottom: medium none; border-left: medium none; border-right: medium none; border-top: medium none;">The development of Central Saint Giles comprises a large 11 storey U-shaped office building to the east, and a smaller, separate 14 storey residential block to the west. All this is arranged around a central public space faced by bars, restaurants and entrance lobbies. It is a really dense group of buildings, providing office, hospitality and residential space on a constrained site in the London West End. Piano's design intention was to reduce the bulk of the buildings in three scales. First, by dividing the complex in two independent buildings (one for office and one for residential) surrounding an inner square. A secondary scale game was to break the large buildings in different heights and angles, so that one thinks the plot is really composed of around ten smaller, residential scale independent blocks. Finally, a wise use of colour and façade detailing further breaks the volumes and introduces a subtle degree of variety, through the use of thousands of individual tiles cladding the multiple separate facades of the buildings. By "fragmenting" the buildings in this way, their scale seems more domestic. <a href="http://4.bp.blogspot.com/_PnCPTb2jz6w/TNgVQsddyWI/AAAAAAAAAI0/ak1v2vZsrNU/s1600/Central+St+Giles+facade+sketch+by+Renzo+Piano.png" imageanchor="1" style="clear: right; cssfloat: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" height="400" px="true" src="http://4.bp.blogspot.com/_PnCPTb2jz6w/TNgVQsddyWI/AAAAAAAAAI0/ak1v2vZsrNU/s400/Central+St+Giles+facade+sketch+by+Renzo+Piano.png" width="386" /></a></div></div><div style="border-bottom: medium none; border-left: medium none; border-right: medium none; border-top: medium none;"><br />
<div style="border-bottom: medium none; border-left: medium none; border-right: medium none; border-top: medium none;">Piano has said about this game:<br />
<i>Fragmentation for me is one of the elements inspired by the place. It was a kind of obsession on this scheme - the spirit of fragmentation of the city, which has been growing in a kind of medieval, organic system.</i><br />
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</div></div><div></div><div><div style="border-bottom: medium none; border-left: medium none; border-right: medium none; border-top: medium none;">Regarding the use of small pieces and the decision to introduce such bold colour into the building, Piano said:<br />
<i>If you want to use brilliant colour, then you have to break down the scale of the façade. The colour idea came from observing the sudden, surprising presence of brilliant colours in that part of the city. I don't think cities should be boring or repetitive. One of the reasons we have such beautiful cities is they are full of surprises.</i><br />
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</div></div><div></div><div>The project team comprised Stanhope, Legal & General and Mitsubishi Estate as developers; Renzo Piano Building Workshop as architects, Fletcher Priest as executive architects and Arup as structural, services, fire and transport engineers. For what interests us in this blog, <a href="http://www.eppag.ch/index.php?lang=english">Emmer Pfenninger</a> have been the façade consultants and <a href="http://www.reefassociates.com/">Reef Associates</a> the façade access consultants. The ground floor glazing parts have been built by Seele, whilst the ceramic and glass facades were built by Schneider Group. NBK supplied the terracotta elements.<br />
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</div><div></div><div><div style="border-bottom: medium none; border-left: medium none; border-right: medium none; border-top: medium none;"><a href="http://1.bp.blogspot.com/_PnCPTb2jz6w/TNgWhZ-aupI/AAAAAAAAAI4/20GNJl4vdQU/s1600/Central+St+Giles+aerial+view+under+construction.png" imageanchor="1" style="clear: left; cssfloat: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="640" px="true" src="http://1.bp.blogspot.com/_PnCPTb2jz6w/TNgWhZ-aupI/AAAAAAAAAI4/20GNJl4vdQU/s640/Central+St+Giles+aerial+view+under+construction.png" width="464" /></a>Central Saint Giles is not a completely new construction, but a large brownfield redevelopment that has lead to the regeneration of a neglected area of central London. The land was formerly occupied by a dull Ministry of Defense building. The new mixed-use space includes 40,000m2 of offices and almost 10,000m2 of housing - 100 apartments – set around a new public square filled with cafes and restaurants. The transparent ground level of the building adds a feeling of permeability at street level, allowing passersby to see through and into the site, accessible by five pedestrian entrances leading into the public piazza.</div><div style="border-bottom: medium none; border-left: medium none; border-right: medium none; border-top: medium none;"><br />
</div></div><div></div><div><div style="border-bottom: medium none; border-left: medium none; border-right: medium none; border-top: medium none;">Renzo Piano has specified ceramic or terracotta cladding for a number of his buildings, starting with two projects in Paris: the IRCAM building (a European institute for electro-acoustical music, finished in 1977) and the Rue de Meaux housing complex (1989-1991). Some other well known terracotta and curtain wall projects by Renzo are the Potsdamer Platz skyscraper in Berlin and the New York Times building in New York. Both use extruded ceramic pieces as sunshade elements, a.k.a baguettes. The approach in London is more complex, since terracotta has been selected here both for the front and the back elements of the facade.</div><div style="border-bottom: medium none; border-left: medium none; border-right: medium none; border-top: medium none;"><br />
</div></div><div></div><div><div style="border-bottom: medium none; border-left: medium none; border-right: medium none; border-top: medium none;"><i>Terracotta is really a modern version of brick, and we felt this material would work well with the surrounding buildings</i>, says <a href="http://www.youtube.com/watch?v=JqntHt-yL-A&feature=related">Maurits van der Staay</a>, the project architect with RPBW. <i>The surrounding brick buildings have a certain depth and we wanted to pick up on that by creating a cladding system with bespoke extrusions that would create different effects – we didn’t want a flat surface.</i></div><div style="border-bottom: medium none; border-left: medium none; border-right: medium none; border-top: medium none;"><br />
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The architect had a team devoted to research on the facade texture - independent from the colour, already decided. During some months a group of <a href="http://www.youtube.com/watch?v=00QPnz7_EHE">young architects led by Lorenzo Piazza</a> played with models at several scales until the decision was more or less clear. The game provided an intersection of horizontal shingle-like pieces with a grill of vertical and horizontal lines, that sometimes crossed in front of the glass units - two bars crossed at the residential windows, three bars at the commercial areas (as shown in the picture above). The vertical bars come in pairs, to provide a feeling of sculpting and shadow, but also because each bar is part of one facade unit behind, and so they can be perceived as a split mullion.<br />
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The ceramic elements on the building, fabricated by <a href="http://www.nbk.de/index.php?idcatside=23&lang=2">NBK in Germany</a>, were mounted on facade units produced by <a href="http://www.schneider-facades.co.uk/">Schneider Fassadenbau</a> at their factory in Wroclaw, Poland. Schneider had some previous experience with combined terracotta and glass-aluminium unitized systems. They had done, also in London, the re-cladding of <a href="http://www.schneider-facades.co.uk/?mod=projects&cat=1&id=9">Collingwood House</a> with Sturgis Associates architects, finished in 2008. For that project Schneider designed a mixed unit system of terracotta-aluminium curtain walling, with fixed brise-soleil set in extruded box frames. The step from Collingwood to Central Saint Giles was natural. To fabricate the whole façade as independent units would be quite convenient, avoiding the use of external scaffoldings after the installation of the glazed façade, thus reducing time and cost. The quality of the end product would also improve, as can be seen by the images of the units being mounted at the Schneider factory in Wroclaw (see images below, with yellow and grey units being fabricated).<br />
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</div></div></div><div style="border-bottom: medium none; border-left: medium none; border-right: medium none; border-top: medium none;"><div style="border-bottom: medium none; border-left: medium none; border-right: medium none; border-top: medium none;"><div style="border-bottom: medium none; border-left: medium none; border-right: medium none; border-top: medium none;"><a href="http://4.bp.blogspot.com/_PnCPTb2jz6w/TNgY9Z2CcII/AAAAAAAAAJA/mes41oU9Ies/s1600/Central+St+Giles+unit+system+at+Schneider+01.png" imageanchor="1" style="clear: left; cssfloat: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="246" px="true" src="http://4.bp.blogspot.com/_PnCPTb2jz6w/TNgY9Z2CcII/AAAAAAAAAJA/mes41oU9Ies/s640/Central+St+Giles+unit+system+at+Schneider+01.png" width="640" /></a></div></div><div style="border-bottom: medium none; border-left: medium none; border-right: medium none; border-top: medium none;">NBK and Schneider worked together a set of detail connections between the terracotta profiles and the aluminium elements behind them. Terracotta profiles completely cover the unit outside face, so that the curtain wall looks like an opaque facade punched by windows (fix units at the offices, opening vents at the housing). The inside face of the panels is clad with white painted aluminium profiles and sheets, no ceramic being present at this side.<br />
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<div class="separator" style="clear: both; text-align: center;"><a href="http://4.bp.blogspot.com/_PnCPTb2jz6w/TNgZRzq2ZVI/AAAAAAAAAJE/A2TfPyYlKs8/s1600/Central+St+Giles+unit+system+at+Schneider+02.png" imageanchor="1" style="clear: left; cssfloat: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="234" px="true" src="http://4.bp.blogspot.com/_PnCPTb2jz6w/TNgZRzq2ZVI/AAAAAAAAAJE/A2TfPyYlKs8/s640/Central+St+Giles+unit+system+at+Schneider+02.png" width="640" /></a></div>There are 18 different terracotta extrusion profiles in six different colours. The extrusions are pressed from a highly sophisticated mix of different types of clay, subsequently dried for several days, and then burned at high temperature for around 24 hours. After being cut to size, the ceramic material is brought on in liquid form, and the pieces are burnt a second time.<br />
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According to NBK, each extrusion has been drawn specially for the project, and further technically fine-tuned between RPBW, Schneider and NBK; each piece has been produced, adapted and tested several times during the design process. The detail below shows the degree of accuracy with which every element interfaces the others. Insulation below the window at section B and behind the jamb at section A is not shown, but it is located there. Terracotta acts as a rainscreen on the outside, with a pressure equalized intermediate space between the outer skin and the glass / aluminium face.</div></div></div></div><div style="border-bottom: medium none; border-left: medium none; border-right: medium none; border-top: medium none;"><br />
</div><div></div><div><div style="border-bottom: medium none; border-left: medium none; border-right: medium none; border-top: medium none;"><div style="border-bottom: medium none; border-left: medium none; border-right: medium none; border-top: medium none;"><div style="border-bottom: medium none; border-left: medium none; border-right: medium none; border-top: medium none;"><a href="http://2.bp.blogspot.com/_PnCPTb2jz6w/TNgZ91HcPHI/AAAAAAAAAJI/aV1jOJwuNAs/s1600/Central+St+Giles+unit+system+detail+from+NBK.png" imageanchor="1" style="clear: left; cssfloat: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="466" px="true" src="http://2.bp.blogspot.com/_PnCPTb2jz6w/TNgZ91HcPHI/AAAAAAAAAJI/aV1jOJwuNAs/s640/Central+St+Giles+unit+system+detail+from+NBK.png" width="640" /></a>All in all there are 3,300 ceramic clad facade units on the buildings (2,300 on the office building and 1000 on the residential building). Each unit contains 32 ceramic elements on a total of more than 400 components. The total number of tiles on the buildings is around 121,000. The ceramic clad facades account for 60% of all upper floor facades.</div></div></div><div style="border-bottom: medium none; border-left: medium none; border-right: medium none; border-top: medium none;"><br />
</div></div><div></div><div><div style="border-bottom: medium none; border-left: medium none; border-right: medium none; border-top: medium none;"><div style="border-bottom: medium none; border-left: medium none; border-right: medium none; border-top: medium none;"><div style="border-bottom: medium none; border-left: medium none; border-right: medium none; border-top: medium none;"><div class="separator" style="clear: both; text-align: center;"><a href="http://3.bp.blogspot.com/_PnCPTb2jz6w/TNgbfxXn9SI/AAAAAAAAAJM/WlwwC6KoSSw/s1600/central+St+Giles+under+construction+01.jpg" imageanchor="1" style="clear: left; cssfloat: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="425" px="true" src="http://3.bp.blogspot.com/_PnCPTb2jz6w/TNgbfxXn9SI/AAAAAAAAAJM/WlwwC6KoSSw/s640/central+St+Giles+under+construction+01.jpg" width="640" /></a></div>Each façade element is approximately 370mm deep, and contains everything: the ceramic extrusions, the aluminium thermally broken frame profiles, the selective coating glass and the opaque infill with thermal insulation. The typical facade unit is 1.5m wide and varies in height from 3.9m for the offices to 3m for the residential. The final cost for the façade units is about £1,100 per m2 (around 1350 €/m2).</div></div></div><div style="border-bottom: medium none; border-left: medium none; border-right: medium none; border-top: medium none;"><br />
</div></div><div></div><div><div style="border-bottom: medium none; border-left: medium none; border-right: medium none; border-top: medium none;"><div style="border-bottom: medium none; border-left: medium none; border-right: medium none; border-top: medium none;"><div style="border-bottom: medium none; border-left: medium none; border-right: medium none; border-top: medium none;">RPBW asked for three full-size mock-ups of the ceramic cladding unit to make sure they got it right, each one a refinement of the last. The most recent mock-up, located at the site, gave the architects the chance to see what the colours would look like in context and they were able to judge whether they had got the balance right between the depth and texture of the unusual ceramic extrusions. The complexity of the perimeter can be seen at the plan here below, with open corners and angled facades.</div></div></div><div style="border-bottom: medium none; border-left: medium none; border-right: medium none; border-top: medium none;"><br />
</div></div><div></div><div><div style="border-bottom: medium none; border-left: medium none; border-right: medium none; border-top: medium none;"><div style="border-bottom: medium none; border-left: medium none; border-right: medium none; border-top: medium none;"><div style="border-bottom: medium none; border-left: medium none; border-right: medium none; border-top: medium none;"><div style="border-bottom: medium none; border-left: medium none; border-right: medium none; border-top: medium none;"><div style="border-bottom: medium none; border-left: medium none; border-right: medium none; border-top: medium none;"><a href="http://2.bp.blogspot.com/_PnCPTb2jz6w/TNgc5KmOxOI/AAAAAAAAAJQ/6iwZX2Cqnag/s1600/Central+St+Giles+plan+with+coloured+facades.png" imageanchor="1" style="clear: left; cssfloat: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="560" px="true" src="http://2.bp.blogspot.com/_PnCPTb2jz6w/TNgc5KmOxOI/AAAAAAAAAJQ/6iwZX2Cqnag/s640/Central+St+Giles+plan+with+coloured+facades.png" width="640" /></a>As the cladding was being installed on site a striking new landmark appeared, defined by dramatic facades of primary colours which at first glance seemed a bold contrast to this neglected corner of central London. Piano is clear about the selection:<br />
<i>The colour idea came from observing the sudden surprise given by brilliant colours in that part of the city. Cities should not be boring or repetitive. One of the reasons cities are so beautiful and a great idea, is that they are full of surprises, the idea of colour represents a joyful surprise.</i><br />
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</div></div></div></div></div></div><div></div><div><div style="border-bottom: medium none; border-left: medium none; border-right: medium none; border-top: medium none;"><div style="border-bottom: medium none; border-left: medium none; border-right: medium none; border-top: medium none;"><div style="border-bottom: medium none; border-left: medium none; border-right: medium none; border-top: medium none;"><div style="border-bottom: medium none; border-left: medium none; border-right: medium none; border-top: medium none;"><div style="border-bottom: medium none; border-left: medium none; border-right: medium none; border-top: medium none;">The façade terracotta comes in six different colours: RAL 070 70 80, RAL 050 50 70, RAL 050 50 78, RAL 000 75 00, RAL 110 60 50 and RAL 7035 Light.</div></div></div></div></div><div style="border-bottom: medium none; border-left: medium none; border-right: medium none; border-top: medium none;"><br />
</div></div><div></div><div><div style="border-bottom: medium none; border-left: medium none; border-right: medium none; border-top: medium none;"><div style="border-bottom: medium none; border-left: medium none; border-right: medium none; border-top: medium none;"><div style="border-bottom: medium none; border-left: medium none; border-right: medium none; border-top: medium none;"><div style="border-bottom: medium none; border-left: medium none; border-right: medium none; border-top: medium none;"><div style="border-bottom: medium none; border-left: medium none; border-right: medium none; border-top: medium none;"><a href="http://3.bp.blogspot.com/_PnCPTb2jz6w/TNgdJigLblI/AAAAAAAAAJU/JrBcr456C8g/s1600/Central+St+Giles+colour+palette.jpg" imageanchor="1" style="clear: left; cssfloat: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="174" px="true" src="http://3.bp.blogspot.com/_PnCPTb2jz6w/TNgdJigLblI/AAAAAAAAAJU/JrBcr456C8g/s640/Central+St+Giles+colour+palette.jpg" width="640" /></a>Central Saint Giles is not just about terracotta. There are three types of facades in the project: </div></div></div></div></div></div><ul><li style="border-bottom: medium none; border-left: medium none; border-right: medium none; border-top: medium none;">the ceramic cladding units in six different colours; </li>
<li style="border-bottom: medium none; border-left: medium none; border-right: medium none; border-top: medium none;">the ground floor double-glazed facades that feature 300mm-deep triple-layered glass mullions evenly spaced apart and located behind the glass; and</li>
<li style="border-bottom: medium none; border-left: medium none; border-right: medium none; border-top: medium none;">the triple fully glazed facades located on the top floors of the office buildings and in the set-back facades between each coloured ceramic-clad facet.</li>
</ul><div><div style="border-bottom: medium none; border-left: medium none; border-right: medium none; border-top: medium none;"><div style="border-bottom: medium none; border-left: medium none; border-right: medium none; border-top: medium none;">There are some slight variations in the office and residential facades. Perhaps the most notable of these are the openable glazed louvres to the winter gardens in the southern corners, an area of special interest for Renzo. Another point of interest is the visitable top roof above part of the office block. In these two elements, Piano creates some intermediate or purely external spaces as venues for the building users. Here the office workers can smoke, sit, chat or just think while viewing the surroundings. The whole complex is not perceived as a massive volume from here.<br />
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<div class="separator" style="clear: both; text-align: center;"><a href="http://2.bp.blogspot.com/_PnCPTb2jz6w/TNgdfGv2roI/AAAAAAAAAJY/kx0xdpXAQQk/s1600/central+St+Giles+terraces.jpg" imageanchor="1" style="clear: left; cssfloat: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="220" px="true" src="http://2.bp.blogspot.com/_PnCPTb2jz6w/TNgdfGv2roI/AAAAAAAAAJY/kx0xdpXAQQk/s400/central+St+Giles+terraces.jpg" width="400" /></a></div><div style="border-bottom: medium none; border-left: medium none; border-right: medium none; border-top: medium none;">The same happens at the ground floor level. Here the architect's intention has been to allow views through the buildings, from the street into the courtyard and from the inside piazza to the outside. The sheer volume seems to float above this glazed podium, without imposing itself upon the street walkers.</div><div style="border-bottom: medium none; border-left: medium none; border-right: medium none; border-top: medium none;"><br />
</div><div style="border-bottom: medium none; border-left: medium none; border-right: medium none; border-top: medium none;"><div style="border-bottom: medium none; border-left: medium none; border-right: medium none; border-top: medium none;">And finally, the facade surfaces. Imagine if these were clad in a flat curtain wall without the richness, texture and shadows of the terracotta fabric. The whole concept would have looked as a huge spacecraft abruptly landed on the West End. The facade <em>is</em> flat - only 370mm deep from inside to outside - in order to maximize the lettable space, but, miracles of architecture, it doesn't look like flat at all. Piano has found inspiration at the terracotta cladding of the best Chicago buildings from the end of the 19th century and their big glazed openings (the Chicago window, remember?). </div><div style="border-bottom: medium none; border-left: medium none; border-right: medium none; border-top: medium none;"><br />
</div><div style="border-bottom: medium none; border-left: medium none; border-right: medium none; border-top: medium none;"><a href="http://2.bp.blogspot.com/_PnCPTb2jz6w/TNgkwUNOgUI/AAAAAAAAAJc/8yItBLWPirI/s1600/Central+St+Giles+back+to+Chicago.jpg" imageanchor="1" style="clear: right; cssfloat: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" height="285" px="true" src="http://2.bp.blogspot.com/_PnCPTb2jz6w/TNgkwUNOgUI/AAAAAAAAAJc/8yItBLWPirI/s400/Central+St+Giles+back+to+Chicago.jpg" width="400" /></a></div>The advantage is double: on one side, the scale is urban, tactile. On the other side, the amount of natural light inside the housing and office spaces is huge, almost as if the facade were a conventional floor-to-ceiling glass element. This seems to me as the perfect balance between a conflicting set of requirements: those of the developers, those of the neighbourhood, those of the city planning department and those of the future tenants. </div><div style="border-bottom: medium none; border-left: medium none; border-right: medium none; border-top: medium none;"><br />
</div>The facade plays a significant role in this achievement, and it has not been an easy task at all. It's tempting to say at first glance that Piano was not at his best this time. After a review of the facts, I would say just the opposite: no one but a master would have been able to reconcile all these requirements and deliver a present to the city. A gift of colour that will keep the area alive for years to come. That's real value for money. That's what architecture is all about.</div></div></div>Ignacio Fernández Sollahttp://www.blogger.com/profile/03918193520738485621noreply@blogger.com13tag:blogger.com,1999:blog-1298203288964657974.post-3500357069802316812010-11-01T08:26:00.390+01:002010-11-01T22:13:03.568+01:00Mokuzai Kaikan: Japanese timber revisited in Tokyo<div class="separator" style="clear: both; text-align: center;"></div>Timber construction is an art, specially when deployed by the crafted Japanese carpenters of past centuries. Apparently, even if there are still artisans who keep some of its secrets today, the subtleties of Japanese timber joinery have disappeared from Nippon architecture. Kengo Kuma is the only name that comes to our mind if we think timber and contemporary Japanese architecture. But projects as interesting as One Omotesando in Tokyo (see the images below), with its main facade protected by thin vertical fins of larch wood, use timber more like a skin care rather than as a construction material. Timber here is the wrapping, not the real thing. The same technique was used by Kengo Kuma at the Nagasaki Art Museum, this time with louvres made of stone instead of timber - although it's difficult to find out from a distance!<br />
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Has timber joinery disappeared from contemporary Japanese architecture then? Well, not yet.<br />
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<div class="separator" style="clear: both; text-align: center;"><a href="http://4.bp.blogspot.com/_PnCPTb2jz6w/TM5sXX7llII/AAAAAAAAAHQ/eDa7gqtWqMk/s1600/One+Omotesando.png" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="187" src="http://4.bp.blogspot.com/_PnCPTb2jz6w/TM5sXX7llII/AAAAAAAAAHQ/eDa7gqtWqMk/s640/One+Omotesando.png" width="640" /></a></div><br />
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<div class="separator" style="clear: both; text-align: center;"><a href="http://2.bp.blogspot.com/_PnCPTb2jz6w/TM5ttph8L2I/AAAAAAAAAHU/ETWHEEgsKng/s1600/art+joinery.png" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="400" src="http://2.bp.blogspot.com/_PnCPTb2jz6w/TM5ttph8L2I/AAAAAAAAAHU/ETWHEEgsKng/s400/art+joinery.png" width="278" /></a></div>'The Art of Japanese Joinery' by Kiyosi Seike is the best introductory book into Nippon wood joinery as an artistic craft. The book starts with the history and philosophy of Japanese architecture as it relates to joinery, then follow many pages of great black and white pictures of wood joints. Only 48 types of joint are presented, selected from among the several hundred known and used today. Joints range from the simple scarf joint to the insanely complex ones. Some of them are truly puzzle-like in construction. The text continues with a chapter on the functions of Japanese joinery, then a chapter on Tsugite or splicing joints and finally Shiguchi or connecting joints, both of which have drawings showing the construction of the joints with hidden lines for further clarification (or obfuscation?)<br />
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Wikipedia will help us enter the world of splice joints or Tsugite. A <a href="http://en.wikipedia.org/wiki/Splice_joint">splice joint</a>, in Japan and elsewere, is a method of joining two members end to end in woodworking. The splice joint is used when the timber pieces being joined are shorter than the length required by the construction. Splice joints are stronger than (unreinforced) <a href="http://en.wikipedia.org/wiki/Butt_joint">butt joints</a> and have the potential to be stronger than a <a href="http://en.wikipedia.org/wiki/Scarf_joint">scarf joint</a>. The most common form of splice joint is the <i>half lap splice</i> (see below left), used in building construction to join shorter lengths of timber into longer beams. Connection has to be achieved using glue, nails or screws. The <i>beavel lap splice</i> gains profit from geometry, with its dovetailed shape. Things start to get more complex with the <i>tabled splice</i> <i>joint</i>, where glue or nails aren't working in shear any longer.<br />
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A variation of the latter is the <i>wedged tabled splice</i> <i>joint</i> (see below right), where two interlocking wedges close the gap and secure the connection of the two timber pieces with each other. Here we don't need to nail or glue the joint and even better, we can disassemble the two pieces if and when needed. We got it: this is Tsugite, we have just entered the Japanese timber joint world.<br />
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Some may think this is nice stuff for DIY aficionados with time to spend on the weekends. Is there a way to apply the intricacies of joinery shown in Kiyosi Seike's book to real life construction? Where will we find the carpenters and the time for doing this - not mentioning the money to pay for it? There is a way, and it's called CNC woodworking machinery. State of the art woodshops today are employing computer numerically controlled pin routers to cut wood, and are using vacuum holding fixtures and autoclave-like devices for joining solid wood. They can even glue wood with glues that harden only in the presence of radio waves. A longish Youtube video - but worth seeing for a couple of minutes - shows one of these <a href="http://www.youtube.com/watch?v=fM0wummBUo8">Japanese timber frame joinery machines</a> at work.<br />
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So timber in Japan is an abundant material, there is a milennary joinery knowledge and there exists CNC machinery to cut and join timber for construction purposes. One would expect to see hundreds of buildings in Japan using timber as structural or as finishing material, both for outside and inside applications. That is not the case though, and this was the reason why Mokuzai Kaikan (the Tokyo Lumber Wholesalers Association) decided to promote timber as the material of choice at their new headquarters in Tokyo.<br />
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<div class="separator" style="clear: both; text-align: center;"><a href="http://4.bp.blogspot.com/_PnCPTb2jz6w/TM6gstHGqZI/AAAAAAAAAHo/rN52zDopnJg/s1600/MK-1.png" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="108" src="http://4.bp.blogspot.com/_PnCPTb2jz6w/TM6gstHGqZI/AAAAAAAAAHo/rN52zDopnJg/s640/MK-1.png" width="640" /></a></div><br />
<div class="separator" style="clear: both; text-align: center;"></div>The Mokuzai Kaikan office project was commisioned to a big architectural firm in Japan, <a href="http://www.nikken.co.jp/en/index.html#back">Nikken Sekkei</a>. The numbers in this studio are impressive: founded in 1900, the firm was 29 strong by 1904 when they finished their first big project, the prefectural library in Osaka with a neo-classical style. Now they are almost 2,900 between architects and engineers, and their projects extend all along the Pacific rim. The Wholesalers Association project was directed by Tomohiko Yamanashi, principal at the architectural design department, in coordination with Takeyuki Katsuya. Yamanashi and Katsuya embraced the idea of promoting the use of timber as requested by their client, and wood became the leit motiv of the project.<br />
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<div class="separator" style="clear: both; text-align: center;"><a href="http://4.bp.blogspot.com/_PnCPTb2jz6w/TM6iSqQGROI/AAAAAAAAAHw/0vEqHCtB6HU/s1600/133_07.jpg" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="548" src="http://4.bp.blogspot.com/_PnCPTb2jz6w/TM6iSqQGROI/AAAAAAAAAHw/0vEqHCtB6HU/s640/133_07.jpg" width="640" /></a></div><br />
<div class="separator" style="clear: both; text-align: center;"><a href="http://1.bp.blogspot.com/_PnCPTb2jz6w/TM6idxAJDWI/AAAAAAAAAH0/PLdhsoTs6ck/s1600/133_05.jpg" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="400" src="http://1.bp.blogspot.com/_PnCPTb2jz6w/TM6idxAJDWI/AAAAAAAAAH0/PLdhsoTs6ck/s400/133_05.jpg" width="265" /></a></div>This is the outline of the Mokuzai Kaikan project as it appears at Nikken Sekkei webpage:<br />
<i>This project involved the relocation of the offices of the Association of Wood Wholesalers in Tokyo. It serves as a showcase to demonstrate the possibilities of wood as an urban construction material. Engawa, or Japanese terraces, allow a natural breeze to enter while shutting out strong sunlight for a comfortable indoor environment. Lumber were integrated into the building's structure, and architectural exposed concrete was cast in cedar formwork. Since the building uses a large amount of wood, great attention was given to fire safety measures. The design focused on creating spatial continuity with the use of layering and natural light.</i></div><div><i><br />
</i></div>The building also revives and adapts another of Japan’s architectural traditions through the use of the Engawa (see night image to the left), a terrace space prevalent in traditional homes. In accordance with earthquake regulations, the 7,582m² seven-storey building employs reinforced concrete for its structural frame. Beyond this, timber was specified wherever possible. The architects paid close attention to detail, fitting the main concrete frame with the secondary timber elements. Concrete was cast in cedar formwork, maintaining the scale and grain of the timber (see below left). </div><div><br />
</div><div class="separator" style="clear: both; text-align: center;"><a href="http://1.bp.blogspot.com/_PnCPTb2jz6w/TM6l1mTECUI/AAAAAAAAAIA/isLdzZl8g1s/s1600/MK-6.jpg" imageanchor="1" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" height="400" src="http://1.bp.blogspot.com/_PnCPTb2jz6w/TM6l1mTECUI/AAAAAAAAAIA/isLdzZl8g1s/s400/MK-6.jpg" width="267" /></a></div><div>In terms of the timber elements themselves, everything that can be seen is formed in 105 x 105 mm sections of Japanese cypress; a standard off-the-shelf product. These sections are used in composite panels to create the distinctive cubic Engawas, but they also form the remarkable longitudinal beams that span the full length of the 25m rooftop assembly hall. Here is where the art of Tsugite reappears, and in a way that mixes tradition with modern requirements. </div><div><br />
</div><div>Each cypress element is just 0.105m high x 4.0m long, and it had to be connected to those above, below and beside to conform a 1.6m high x 25m long beam. The connection system owes something to the traditional joinery - you can see timber wedges in vertical, combined with wooden oak plugs that connect every two pieces in horizontal. Tabled spliced joints can be seen both at the top and the side of every element. But there are also stainless steel rods - or should we say long bolts? - that keep all timber pieces working together as a 1.6m high beam. In order to avoid the concentrated tension around bolts to fracture the wood under extreme stress, cilindrical aluminium rings have been added around each passing bolt. </div><div><br />
</div><div>The exploded detail can be seen here below, extracted from an article about the Mokuzai Kaikan office appeared on <a href="http://www.architectural-review.com/skill-/mokuzai-kaikan-office-by-tomohiko-yamanashi-and-takeyuki-katsuya-nikken-sekkei-shinkiba-tokyo-japan/5218274.article">The Architectural Review</a>. The following images, the assembly room plan at the upper storey, the vertical section and the Engawa 3D drawing have also been taken from the same article.</div><div class="separator" style="clear: both; text-align: center;"><a href="http://1.bp.blogspot.com/_PnCPTb2jz6w/TM6s9CWEG0I/AAAAAAAAAIE/PIr5QkJI5lg/s1600/MKD-1.png" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="464" src="http://1.bp.blogspot.com/_PnCPTb2jz6w/TM6s9CWEG0I/AAAAAAAAAIE/PIr5QkJI5lg/s640/MKD-1.png" width="640" /></a></div><div><br />
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</div><div>The Mokuzai Kaikan office was built between Nov 2007 and June 2009. The project received a Special Jury Award at the 3rd annual MIPIM Asia Awards 2009 held in Hong Kong. I invite you to see some stunning <a href="http://www.chousing.info/Architecture-in-Japan/Mokuzai_Kaikan.html">images of the interior here</a> (go to the bottom of the page)</div><div><br />
</div><div>How will the lumber perform on the outside say 10 years from now? This remains to be seen. I have not found any information about the surface treatment these cypress logs have undergone - if someone out there knows more, please shout. One final critique has to do with the side facade, visible at the images from the link above. That facade doesn't seem to be the best part of the building. But all in all, Mokuzai Kaikan is a great example of architecture well delivered at all levels, from the concept phase to the 1:1 details, from programme to materials selection. The front facade is an example of intermediate, filtering space, one that moves forward from the typical flat, barrier-like glazed facades we are used to these days. </div><div><br />
</div><div>There is another project I find vaguely similar to this one, located in a very different place place and context: Louis Kahn's Salk Institute at La Jolla in California (1959-1966). Sorry, but I can't find a better way to finish this post than by paying a little homage to the old master.</div><div><br />
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</div>Ignacio Fernández Sollahttp://www.blogger.com/profile/03918193520738485621noreply@blogger.com8tag:blogger.com,1999:blog-1298203288964657974.post-30107360968726093452010-10-30T17:54:00.012+02:002010-11-04T22:16:13.459+01:00The Ledge at the Sears Tower in Chicago: glass is the limitThere can't be more stories written about the design, engineering and construction of such a small part of a building as for The Ledge, the latest attraction at the tallest observation point in Chicago. The Ledge is really small in number: just four glass boxes, all the same. And it's small in size too: each box is 1.3 x 3.2m in plan, and close to 3.6m high. But there's one detail that makes all the difference: these four fully glazed boxes are cantilevered from the 103rd floor of the Sears Tower, at 413m above the ground. Glass Google pages and technical papers at recent facade conferences are filled with stories about it. <br />
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Why so much fuss about glass boxes? Well, the image says it all.<br />
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<div class="separator" style="clear: both; text-align: center;"><a href="http://4.bp.blogspot.com/_PnCPTb2jz6w/TMQ8PN02G9I/AAAAAAAAAG0/l8C3be7VH3s/s1600/willis+tower+ledge+view.jpg" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="450" src="http://4.bp.blogspot.com/_PnCPTb2jz6w/TMQ8PN02G9I/AAAAAAAAAG0/l8C3be7VH3s/s640/willis+tower+ledge+view.jpg" width="640" /></a></div>The Sears tower (since 2009 sadly renamed as Willis tower) remains the tallest building in the Western hemisphere. Completed in 1973, its 442m (without counting the spires) are still today an impressive height for a building. The Sears tower observation deck, called the Skydeck, is located on the 103rd floor of the tower, and its view 412 m above ground is one of the tourist attractions in Chicago. Visitors, up to now, could experience how the building sways on a windy day. Now they can also feel a different sensation: that of sheer vertigo.<br />
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In January 2009 the tower owners began a major renovation of the Skydeck including the installation of four glass balconies, extending approximately 1,2m over the west facade from the 103rd floor. The all-glass boxes allow visitors to look through the floor to the street 412m below. The Ledge opened to the public on July 2009.<br />
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The Skydeck renovation project <a href="http://www.som.com/content.cfm/sears_tower_observation_deck">was awarded to Skidmore Owens and Merrill</a> (SOM), the architects who designed the tower. The picture above shows a realistic image of their intention: glass all around, no steel structure at all if possible. “The Sears Tower set architectural and engineering standards when it was first built and now we are able to carefully craft new elements that expand the capabilities of the original design while retaining its integrity,” said Ross Wimer, design partner with SOM and one of the fathers of The Ledge idea. <a href="http://www.360cities.net/image/sears-tower-skydeck-window-chicago#298.00,5.60,70.6">A 360º view of one of the glass boxes</a> (this is not a render) is the nearest you can be to the real sensation of stepping in (or out?) there.<br />
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<div class="separator" style="clear: both; text-align: center;"><a href="http://1.bp.blogspot.com/_PnCPTb2jz6w/TMw_IH5QrWI/AAAAAAAAAG8/Z_IxRH5JCkE/s1600/from+below.png" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="640" src="http://1.bp.blogspot.com/_PnCPTb2jz6w/TMw_IH5QrWI/AAAAAAAAAG8/Z_IxRH5JCkE/s640/from+below.png" width="425" /></a></div>Architects must be praised for the idea, but engineers - glass specialists - were needed for its detailed design and realization. The building owners contracted Halcrow Yolles<span class="Apple-style-span" style="font-family: Helvetica; font-size: xx-small;"><span class="Apple-style-span" style="font-size: 9px;"> </span></span>in Toronto as engineers for the observation boxes, and gave them the responsibility of fully design and detail the glass and steel components. Halcrow's senior principal and structural glass engineer was at the time John Kooymans, one of the few who can say 'The Ledge is my baby'. Around the end of 2009 John moved from Halcrow to another Canadian engineering team, MTE Consultants in Ontario (the name means More Than Engineering). If you visit Halcrow and MTE webpages you will find how both companies claim having authored the engineering design of The Ledge - and both are right!<br />
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There are two articles describing the design of the glass boxes both written by John Kooymans, one as part of Halcrow Yolles and the other one written this year as member of MTE. According to the first paper, <a href="http://www.glassfiles.com/library/20/article1493.htm">publised in Glass Performance Days 2009</a>, the challenges to solve were many:<br />
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<ul><li>All glass elements had to be brought up to site using the internal elevators, which limited the size of the box elements.</li>
<li>The observation boxes had to be moveable. This was required to allow the facade maintenance equipment to operate along the facade without interruptions. But, even more difficult, it was decided that the glass boxes were to be retracted an additional 1200mm into the floor space, so that glass maintenance and cleaning could be done from inside the building.</li>
<li>There was tenant at the floor below the Skydeck, so all the glass box loads had to be hanged and framed from the ceiling above, in order to avoid interferences.</li>
<li>Design loads and movements to be imposed onto the glass structure would be very high from the calculation stage. The frame and glass box had to be stiff enough to allow the movement of the box without creating large deformations or stresses at the glass connections.</li>
<li>The details around the glass box had to include weather seals in both the extended and retracted position, allowing for the movement of the tower, and for the seal to be temporarily broken while the assembly moved from one position to the next.</li>
<li>The architectural intention was to obtain maximum transparency, including the floor and the roof, minimizing the visible structural steel elements.</li>
<li>Structural redundancy (safety) and protection of the glass were requested. But, to speed the use of the balconies, visitors would not be forced to protect their shoes when entering. Safety issues excluded the option of double glass, and laminated glass was the solution.</li>
<li>Outer temperatures should not create a risk of condensation on the glass, or worse allow the formation of ice shards outside the boxes, falling onto the walkway behind. So, the design had to introduce some kind of heating system as well.</li>
</ul><a href="http://1.bp.blogspot.com/_PnCPTb2jz6w/TMwxuisOQ4I/AAAAAAAAAG4/gjcchrNaWBg/s1600/Ledge+concept+1.png" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="351" src="http://1.bp.blogspot.com/_PnCPTb2jz6w/TMwxuisOQ4I/AAAAAAAAAG4/gjcchrNaWBg/s640/Ledge+concept+1.png" width="640" /></a><br />
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The second paper by John Kooymans is the one that originated this post: I read it at the proceedings of Engineering Transparency, a conference held in Glasstec Düsseldorf last 29 and 30 September. Carlos Prada and María Meizoso, two colleagues from Arup Facades Madrid, attended the conferences and brought the news back to us. You can have <a href="http://www.mte85.com/documents/The%20Ledge_Engineering_Transparency_Conference.pdf">access to the paper here</a>, through the MTE webpage.<br />
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Each box face can withstand design wind pressures of 4.6 kPa, and the roof and floor wind pressures of 6.0 kPa. At the floor there is an additional live load of 4.8 kPa due to its intended occupancy. As Kooymans puts it, it can essentially hold more people than it can fit.<br />
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The corners and intermediate joints where the different wall panels come into contact with each other are simply stitched together with stainless steel angles and through bolts. The floor is stitched to the glass walls creating small local opaque connections that allow for the transfer of external loads into the hanging glass panels and subsequently, into the steel cantilevered frame.<br />
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From John's Glasstec paper:<br />
<i>The glass had to be designed with enough redundancy to ensure that any accidental breakage would not result in a total collapse of the system. For this reason, three layers of glass were selected for all the elements. The structure was designed so that only two layers of glass were required to resist the design loads, and only one layer of glass would be able to support the self weight of the structure. In addition to this design decision, the glass floor was constructed using an ionoplastic interlayer (SentryGlas Plus) captured by the through bolts in the floor which would ensure the stiffness of the tempered floor panel would remain intact in the remote possibility that all three structural glass lites failed.</i><br />
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In the end, the glass box elements are all created with three layers of 12 mm tempered low iron, heat-soaked glass. The requirement of heat-soaking helped eliminate the potential for spontaneous breakage due to nickel-sulphide inclusions.</i><br />
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If the engineers of The Ledge were Canadians, the facade contractors are pure Chicagoans, and making part of the city building history. <a href="http://www.mthindustries.com/">MTH Industries</a>, located in Hillside, Illinois, started building glass facades in Chicago back in 1886. Upon first hearing about the project, Ludek Cerny, vice-president of glazing at MTH Industries, thought it was pretty unusual. Because of that, MTH wound up taking on a design-assist role.<br />
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<a href="http://4.bp.blogspot.com/_PnCPTb2jz6w/TMxDri-T1AI/AAAAAAAAAHA/8j7KgJTwge0/s1600/mock+up.png" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="233" src="http://4.bp.blogspot.com/_PnCPTb2jz6w/TMxDri-T1AI/AAAAAAAAAHA/8j7KgJTwge0/s640/mock+up.png" style="cursor: move;" width="640" /></a><br />
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Load tests done in-house by the contractor (see images above) involved loading a glass lite that was half the size of the actual floor of the bays to 2½ times the required code load for a 24-hour duration. “The test was later repeated with fracturing one of the lites with the actual design load,” Cerny says. That wasn’t enough for this team: “Out of curiosity,” Cerny says, “we actually broke more lites and realized that you could still stand on the glass floor with all of the lites broken.” Miracles of ionoplastic interlayers.</div><br />
In addition to avoid damage from breakage, the design includes ways of protecting the bays from daily wear as well. There is an anti-graffiti film on the inside of the vertical glass units. The laminated floor has a 6mm sacrificial layer of fully tempered, heat-soaked glass on top that can be removed or replaced if it gets scratched, cracked or damaged. The stainless steel fasteners that support the glass panes to each other are bespoke and have been custom-machined by MTH.<br />
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The motorized system that projects and retracts the boxes from the building utilizes steel LinearBeam mechanical linear actuator systems. The systems operate with a rigid chain technology. A rigid chain is a mechanical actuator that is flexible in one direction and forms a steel beam in the other direction. The contractor worked with the supplier to design the locking pins and the control systems that secure the bays.<br />
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Because of the movement, the perimeters of the bays are lined with inflatable seals. When the bay is in the viewing (outside) or in the maintenance (flush) position, the seals inflate to create a secure air and water lock for the building. <br />
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Vertical movement - that is, transporting the box material up to the 103rd floor - proved to be one of the bigger challenges for the contractor. The installers moved the glass units and the 5.5m suspension beams up on the top of elevator cars. To ease the material handling, MTH ended up creating custom tools to help hoist and carry. “It was all a conglomeration of things that already existed modified to work under these conditions in the space allowed,” Cerny adds.<br />
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<b><span class="Apple-style-span" style="font-weight: normal;">The laminated glass units forming the walls and the roof have three tempered 12mm lites of PPG's Starphire low-iron glass. The walls and roof are laminated with clear PVB, while the floors are laminated with 1,52mm <a href="http://www2.dupont.com/SafetyGlass/en_US/assets/pdfs/sentryglas-skydeck-glass-floor.pdf">DuPont’s SentryGlas Plus</a> interlayers. The glass fabricator was Prelco of Montreal. Prelco delivered its last panel in April 2009, six months after the company began fabrication and two months before the end of the installation on site.</span></b><br />
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This article from <a href="http://www.nytimes.com/2009/07/07/science/07glass.html">The New York Times</a> has a very interesting short video abour the building of the Ledge. Scroll down and you'll find it on the right. Not to be missed!<br />
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The final image is my personal homage to the vision of all the people involved in getting these glass boxes real: from the owner to the architect, engineer, contractor and every supplier. Compare this image with the first render, drawn by the architects in 2008. One year later, the built thing is astonishingly similar to the design intention. In fact, it is even better: by selecting low iron glass, the green aspect of the standard glass used in the first image has disappeared.<br />
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</div><div>Could such a small job have been done better? </div>Ignacio Fernández Sollahttp://www.blogger.com/profile/03918193520738485621noreply@blogger.com5tag:blogger.com,1999:blog-1298203288964657974.post-70495076634845013642010-10-16T00:17:00.006+02:002010-10-16T10:44:06.188+02:00Arup and facade engineeringThis is my post nº 22. This blog has had more than 1,100 visits up to now, in less than two months after I started writing it. Not bad!<br />
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<div class="separator" style="clear: both; text-align: center;"><a href="http://1.bp.blogspot.com/_PnCPTb2jz6w/TLjLmL41MfI/AAAAAAAAAGo/V3nlFLLeCXM/s1600/Arup+logo.png" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="58" src="http://1.bp.blogspot.com/_PnCPTb2jz6w/TLjLmL41MfI/AAAAAAAAAGo/V3nlFLLeCXM/s200/Arup+logo.png" width="200" /></a></div>It's time to get a bit more personal, and tell you, dear reader, what I do for a living. I am a facade engineer, or a facade specialist, or a facade consultant - it's all the same more or less. I work in <a href="http://www.arup.com/">Arup</a>, a big engineering firm based in London but with offices in all continents. My desk is in Madrid, but my projects are - and have been - in many places around the world. That's of course a fantastic experience.<br />
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There are almost 300 facade engineers in Arup if we count all offices. The discipline started in London around 1985, and I think we are now the biggest facade consultant in the world. Our offices with facade dedicated teams are located in the UK, Ireland, Germany, Italy, Netherlands, Spain, Denmark, Dubai, South Africa, Australia, Singapore, China, Japan and the US. The facades team in Madrid started in 2004, and we are 10 people between architects and engineers. We have taken part in projects as interesting as the image below: the <a href="http://www.arup.com/Projects/Zaragoza_Expo_Pavilion_Bridge.aspx?sc_lang=en-GB">Bridge Pavillion in Zaragoza</a> with Zaha Hadid. We have been lucky enough to work with well-known architects as Rogers, Foster, Zaha, Piano, Chipperfield, Arup Associates, or Spanish firms as Rafael de La-Hoz, Lamela, Nieto Sobejano, DL+A, MBM, Ferrater, Vidal or Cruz y Ortiz. We also work for developers, usually helping architects to develop the trickiest parts of facade designs, acting as site specialists during construction, conducting failure investigations or leading the facade refurbishment of existing buildings. Sometimes we also do systems research and development for facade contractors.<br />
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<div class="separator" style="clear: both; text-align: center;"><a href="http://2.bp.blogspot.com/_PnCPTb2jz6w/TLjLV53hoYI/AAAAAAAAAGk/tVgqrauLtQA/s1600/pab+pte.jpg" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="126" src="http://2.bp.blogspot.com/_PnCPTb2jz6w/TLjLV53hoYI/AAAAAAAAAGk/tVgqrauLtQA/s640/pab+pte.jpg" width="640" /></a></div>I love being a facade engineer because of the combination of skills it requires. As old Vitruvius used to say, it has a bit of <em>firmitas</em> (resistance, durability), a bit of <em>utilitas</em> (performance, confort, modularity) and a bit of <em>venustas</em> (proportion, colour, texture, beauty). Wasn't it the definition of architecture? Precisely. The question is that these days, because of the complexity of the building profession, one cannot be an architect and understand everything of a building in a holistic way. There are two options: either you remain a generalist and rely on teamwork for the project to achieve a global view, or you become a specialist in one specific area of knowledge, as facades. In this case you can still have a complete understanding of your branch, combined with a minimum amount of details of the surrounding areas. Engineers have always tended to subdivide their bodies of knowledge; architects have up to now resisted such a temptation. As an architect, I think we were wrong. Someone can argue that my work is not that of an architect, but of a building engineer. I take the point: being a building engineer is a way of being an architect, just as being a civil or an electrical engineer are ways of being an engineer.<br />
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Facades are a great topic because they involve almost everything an architect did in the good old days (except plan distributions obviously), so you still feel you are in command, and your area of expertise is still very wide. In fact, I now consider myself a facade generalist rather than a facade specialist - it's becoming impossible to be a real specialist in such a wide discipline as ours!<br />
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<div class="separator" style="clear: both; text-align: center;"><a href="http://1.bp.blogspot.com/_PnCPTb2jz6w/TLjKyHeQm3I/AAAAAAAAAGg/lcs4fYBGsn8/s1600/sfelogo.jpg" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="320" src="http://1.bp.blogspot.com/_PnCPTb2jz6w/TLjKyHeQm3I/AAAAAAAAAGg/lcs4fYBGsn8/s320/sfelogo.jpg" width="229" /></a></div>British people love belonging to clubs. Today's equivalent to the classic clubs are professional fellowships, where Brits feel like at home with their peers. Times have changed for good, and these professional societies do welcome women and foreigners as members. Our club is of course the<a href="http://www.facadeengineeringsociety.org/"> Society of Façade Engineering</a>. And what is the definition of façade engineering to this honourable Society? There it goes:<br />
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<i>“Façade engineering is the art of resolving aesthetic, environmental and structural issues to achieve the enclosure of habitable space.” </i><br />
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<i></i>You see? There's Vitruvius again, and I swear I wasn't aware of this definition until now. Sounds good to me (and rather Brit as well). The Chairman of the Society is my friend and Arup colleague Mikkel Kragh. Mikkel is Danish as Ove Arup, our founding father, which makes him a sort of square Arupian. He is now living in Milan and leading a growing Arup Facade team there, apart from chairing the Society and doing several research and academic activities. Mikkel has written an article on the role and challenges of façade engineering, "<a href="http://www.facadeengineeringsociety.org/kragh-paper.pdf">Façade engineering and the design teams of the future</a>". He points out that our trade is not only a business of architects and engineers, but also one for facade contractors:<br />
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<i>The façade engineering discipline is embedded in various aspects of the work of Architects, Engineers, and Specialist Trade Contractors and we will see an increasing need for seamless collaboration and delivery of integrated systems as opposed to elements and components. We have witnessed a recent trend of design teams going from multidisciplinary to interdisciplinary, with disciplines interacting and working closer together.</i><br />
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<div><a href="http://1.bp.blogspot.com/_PnCPTb2jz6w/TLjOPSjFuCI/AAAAAAAAAGw/6XbjtLejgf8/s1600/Galleria_west_Shopping_Centre_218x327_c_Christian_Richters_Arup.ashx.jpg" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="400" src="http://1.bp.blogspot.com/_PnCPTb2jz6w/TLjOPSjFuCI/AAAAAAAAAGw/6XbjtLejgf8/s400/Galleria_west_Shopping_Centre_218x327_c_Christian_Richters_Arup.ashx.jpg" width="266" /></a>This is a really serious point: integrated systems as opposed to elements and components. The integration of different functions, not just the co-existence of independent systems as part of one skin, seems to be the strategy for the future of façade technology and design. I believe this is the way too. There is more on this matter in a paper from Tillman Klein, who leads the Façade research group at the Faculty of Architecture in Delft, "<a href="http://books.google.es/books?id=chAA7sDn0koC&pg=PA85&lpg=PA85&dq=evolution+revolution+systems+facade+technology+klein&source=bl&ots=Z7xJmB3Rj-&sig=KNpK6mpnF2WRa7uFnCl1KRgok6s&hl=es&ei=Qsm4TP-cENfPjAeHkOXEDg&sa=X&oi=book_result&ct=result&resnum=1&ved=0CBgQ6AEwAA#v=onepage&q=evolution%20revolution%20systems%20facade%20technology%20klein&f=false">Evolution or revolution of systems in façade technology</a>". This article is part of the book "The future envelope 1 - a multidisciplinary approach", edited by Ulrich Knaach and Tillman Klein.</div><div><br />
</div><div>But design and construction are just parts of the whole story of facades. New materials, the quest for optimum energy performance or the support for energy generation systems are requirements that meet with predominantly conventional crafts. Our role as façade engineers in every project is to lead a conversation between these diversely interested disciplines into a converging interdisciplinary team, a team that will not put one interest too much above the others. It sounds like a complex task, but the final result should be simple: as the good movies or buildings we remember long after having seen them. </div><div><br />
</div><div>Should we façade engineers expect to receive prices or accolades? Nope. By the time for the party and the distribution of medals after the opening of a building we are already hands on with the next project, where the action - and the learning - is. Our medal is to have taken an active role in designing, fabricating and building facades that stand the passing of time, perform well and mean something to people. Our medal is to have avoided failure to happen more than once. Our medal is to contribute to the delivery of better buildings that become sounding pieces of better cities. </div><div><br />
</div><div>Isn't it a great career?</div><div><br />
</div>Ignacio Fernández Sollahttp://www.blogger.com/profile/03918193520738485621noreply@blogger.com4tag:blogger.com,1999:blog-1298203288964657974.post-63637505658057049142010-10-10T18:39:00.445+02:002010-10-13T12:51:15.535+02:00Cook vs Gehry on designing the best NYC skyscraperLast August Paul Goldberger, The New Yorker’s architecture critic, spoke with Richard Cook, founder and partner in Cook+Fox Architects and the designer of the new Bank of America Tower. The Manhattan skyscraper, a.k.a. One Bryant Park, was completed earlier this year and is the largest commercial building to receive a LEED Platinum certification, the highest standard set by the U.S. Green Building Council. Cook and Goldberger indulge in a <a href="http://www.newyorker.com/online/blogs/currents/2010/08/richard-cook.html">polite conversation</a> about sustainable design, LEED certification and the meaning of green consciousness for architects nowadays.The critic does not perform as a critic; he seems convinced by the elegant, soft-spoken and well-educated leader of Cook+Fox Architects. My impression - I must admit it - was not so positive. There is something about this glazed tower that seems rather opposite to the concept of a sustainable building, and that's the huge amount of vision glass that covers the facade top to bottom. A similar percentage of vision glass than at the Lever House or the Seagram Building, to name just two icons of New York curtain walls in the 20th century.<br />
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<div><div class="separator" style="clear: both; text-align: center;"><a href="http://2.bp.blogspot.com/_PnCPTb2jz6w/TLIxDMOK6oI/AAAAAAAAAF0/YyCq2SRq8gI/s1600/BP+1.jpg" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="640" src="http://2.bp.blogspot.com/_PnCPTb2jz6w/TLIxDMOK6oI/AAAAAAAAAF0/YyCq2SRq8gI/s640/BP+1.jpg" width="425" /></a></div></div><div>The message in the video was well packaged and sent though. A quick review to the <a href="http://environment.bankofamerica.com/article.jsp?articleId=Tower">Bank of America</a> Web page brings some more info:<br />
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</div><i>Bank of America Tower at One Bryant Park is the heart of our New York operations - and a striking example of our environmental commitment. The 55-story tower, having obtained the U.S. Green Building Council's LEED® (Leadership in Energy and Environmental Design)- CS Platinum certification, is one of the world's most environmentally responsible high-rise office buildings.</i><br />
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Unlike most large buildings, the tower will generate a significant portion of its power on site through a 5.1 megawatt cogeneration system. It also will save about half the energy used by most buildings its size; will filter out about 95 percent of the particules in the air drawn into the building; will use less expensive night-time power to produce ice used to cool the building; and will conserve millions of gallons of water every year through methods such as green roofs and waterless urinals.</i><br />
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<div><div class="separator" style="clear: both; text-align: center;"><a href="http://3.bp.blogspot.com/_PnCPTb2jz6w/TLIxTMbHI2I/AAAAAAAAAF4/zxgjtOEhu_I/s1600/BP+3.jpg" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="388" src="http://3.bp.blogspot.com/_PnCPTb2jz6w/TLIxTMbHI2I/AAAAAAAAAF4/zxgjtOEhu_I/s640/BP+3.jpg" width="640" /></a></div>Even the <a href="http://www.huffingtonpost.com/2010/08/25/1-bryant-park-tower-gets-_n_692796.html">Huffington Post</a>, a reliable NYC politics and socialite Web page (not precisely conservative) seems to have joined the praise.<br />
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There is another tower in Manhattan, still under construction, which is not known by its sustainable credentials but by its designer, Frank Gehry. The Beekman tower, located just south of City Hall, has recently received a positive review at the <a href="http://www.nytimes.com/2008/05/31/arts/design/31beek.html?_r=3&ref=design&oref=slogin">art & design pages of The New York Times</a>. The 76-story tower is recognizable by its crinkled stainless steel skin, bringing a new look to an imposing cluster of landmarks from a hundred years ago commanded up to now by the Woolworth Building.<br />
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The design of the Beekman tower has evolved through an unusual public-private partnership. In an agreement with New York education officials, the tower’s developer, Forest City Ratner, agreed to incorporate a public elementary school into the project. Forest City was responsible for the construction of the school; the Department of Education then bought the building from the developer. The Beekman tower is thus a curious fusion of public and private zones. Clad in simple red brick, the school will occupy the first five floors of the building. Atop this base will be the elaborate stainless-steel form of the residential tower.</div><div><br />
</div><div>As IBM ads tell, it's time to ask smarter questions. From the available literature, Cook+Fox are the nice, responsible guys whilst old Gehry, in his Southern Californian mood, has come to Manhattan just for the money. Is it as simple as that? Not really.<br />
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Let's have a look at the vertical section of One Bryant Park:<br />
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Two-thirds of the facade surface - floor to ceiling - are covered with vision glass, only one-third - the edge of slab - is opaque glass with a back-panel insulation. The tower has been clad with Viracon insulated glass with a low-e coating and a silk-screen pattern made of fritted dots on the #2 surface. To allow for higher transparency, the glass is low iron (extra clear). At eye level (sit or standing) the glass has no pattern, providing great views of the New York skyline. The silk-screen pattern extends graduately below eye level to the floor and above eye level to the ceiling to reduce radiant heat gains. These are the best data I could find<span class="Apple-style-span" style="font-family: Geneva, Helvetica, sans-serif;"><a href="http://www.viracon.com/downloads/resources/SustainableDesign.pdf"> from the glass supplier</a>, </span>not from the project, so take it as a guess (the glass coating is a project specific combination of VE 15-2M and VRE 15 -59 from Viracon): U-value 1.6 W/m2ºK or 0.30 BTU/hft2ºF, solar heat gaining coefficient between 0.36 and 0.39, visible trasmittance between 55% and 73%.<br />
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“Bringing in more daylight deep into the building reduces electricity costs. But it also increases the efficiency of the people that work in the builiding – and that's the greatest cost savings,” says a spokesperson from the developer, adding that financial firms' personnel costs are several factors higher than their energy needs. “If you're 10% more efficient on energy, it's not the same dollar amount as a 2-3% in personnel savings"<br />
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This sounds familiar to most of us involved with glass and energy efficient buildings. The architects seem to have convinced the developer that lots of light are good for tenants, and energy losses (or gains) through the glass are secondary. The solar passive behaviour of a glazed tower must be relative, since it doesn't impede the building to achieve a LEED platinum certification. It is true if you use LEED as the only metering system, but it is not true if you really try to minimize the total heat exchange through your facade. Lets have a look now at the curtain wall unit system detail (vertical section through the top-bottom interlocking transom):<br />
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The glazing contractor for the project, by the way, is Permasteelisa USA. Do you miss anything in this section? I do: a good old thermal break in the transom profiles. OK, so we have here a non-thermally broken unit system with a combination of 2/3 vision glass (U-value of 1.6 W/m2K centre pane) and 1/3 opaque glass (100mm of mineral wool plus insulated glass, that should be around 0.6 W/m2K centre pane).<br />
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<div class="separator" style="clear: both; text-align: center;"><a href="http://4.bp.blogspot.com/_PnCPTb2jz6w/TLRzAIuiNuI/AAAAAAAAAGI/VRL4xRHAo4U/s1600/BP+cw+on+site.jpg" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="301" src="http://4.bp.blogspot.com/_PnCPTb2jz6w/TLRzAIuiNuI/AAAAAAAAAGI/VRL4xRHAo4U/s320/BP+cw+on+site.jpg" width="320" /></a></div>We Europeans may be a bit pesimistic when doing U-value calculations, but the combination of those three elements (profiles, vision and spandrel glass), according to our standards, delivers an overall U-value between 1.9 to 2.3 W/m2K. Let's add to it the radiant heat gains: all orientations have the same glass, there are no external shading systems, and 2/3 of the glass is vision, with an average solar heat gain coefficient of around 0.35 (deducting the profiles but adding the radiant heat that enters through the non-thermally broken aluminium). What does this mean? Two things: important heat losses in winter and very important heat gains in summer, both along the whole working day. As a result, a) services must have been designed to cover peak loads, at an important extracost, and b) energy consumption along the year will be clearly higher than if designed otherwise. The energy performance of this curtain wall is much better than the Seagram or the Lever House from the 50s, of course, but it's nothing extraordinary nor any example of energy efficiency in buildings. I will skip the glare issue here, but I bet not all Bank of America clerks are happy about their transparent facade when they try to read their computer screen at the office.<br />
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But then, who is wrong? Wasn't it an example of environmental commitment? According to LEED, yes it is. According to some of us, there is much room for improvement - both in the design of this facade and in the way LEED points are measured and obtained. You can find more on the matter at this interesting webpage, written by Steve Mouzon: <a href="http://www.originalgreen.org/OG/Blog/Entries/2010/7/2_1_Bryant_Park_and_the_LEED_Problem.html">One Bryant Park and the LEED problem</a>. I completely agree with his point of view about LEED: the US Green Building Council has made a lot for achieving better buildings and deserves our praise, but it's time for a change in the way LEED points are given. One sole change to begin with, please: all Gold and Platinum pre-qualified buildings should measure their energy output once they are built and occupied, and compare real life results against simulations, if they want to receive the final medal.<br />
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<div class="separator" style="clear: both; text-align: center;"><a href="http://3.bp.blogspot.com/_PnCPTb2jz6w/TLR4YcuQ_mI/AAAAAAAAAGM/gpdrKqRQ21s/s1600/Bee+1.gif" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" src="http://3.bp.blogspot.com/_PnCPTb2jz6w/TLR4YcuQ_mI/AAAAAAAAAGM/gpdrKqRQ21s/s1600/Bee+1.gif" /></a></div>Time to come back to our old Frank Gehry and his slender residential Beekman tower. The developer here has not opted for a LEED certification (at least that I know). Compared to One Bryant Park, though, the project is quite reasonable in terms of facade energy performance.<br />
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The stainless-steel folds that now drape all but the top few floors of the <a href="http://continuingeducation.construction.com/article.php?L=5&C=695&P=1">Beekman Tower</a> have already created a new landmark on Lower Manhattan. “I designed this building for New York,” says Gehry. “I’m a deeply rooted contextualist regardless of what anybody says. I stair-stepped the building like a New York skyscraper. It fits in without pandering to, or copying, its neighbors”.<br />
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To produce the tower’s wavy skin in a cost-efficient process, the facade concept is based on a flat, unitized curtain wall with a back-ventilated rain-screen cladding attached to its front. Permasteelisa (once again) was selected as the facade contractor. You will read lots of papers about the computer design process, Rhino, Catia, etc. This is not our stuff right now, we are just onto sustainable performance today.<br />
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Let's have a look at a the facade plan section. The folds of the facade become something as bay windows for the apartments, providing top and lateral shadows along the day. The residents will feel they are living within thick walls, at least that's the impression one gets from the plan section. This is a good feeling, don't you think?<br />
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The amount of opaque surfaces in this facade is much bigger than at One Bryant Park. All columns, partitions and parapets are clad with 16-gauge stainless steel face sheets, hiding a thick mineral wool insulation behind. The curtain wall elements are thermally broken. I haven't found any data about the glass yet, but I bet it's a low-e double glass unit without any additional coating.<br />
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The external wall looks really well from a nearby position. OK, stainless steel is not cheap, and these flumsy shapes are not easy to do. Even though, if we conducted a life cycle analysis of this facade, I wouldn't be surprised to find out that the low energy transmission - both during winter and summer - plus a low maintenance operation cost can offset the extra construction cost in a few years, making this facade more sustainable in the long term than the Bank of America's one. LEED permitting, of course.<br />
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Who knows? Maybe Gehry is more aligned with the real spirit of New York facades than Cook+Fox: a spirit that favours tall, vertical windows, stepped-back volumes and decorated external walls. There's nothing wrong about it, after all...</div></div>Ignacio Fernández Sollahttp://www.blogger.com/profile/03918193520738485621noreply@blogger.com3tag:blogger.com,1999:blog-1298203288964657974.post-42860126271613572602010-10-04T22:58:00.120+02:002010-11-01T16:15:29.049+01:00Industrialized building speech<span class="Apple-style-span" style="font-family: 'Lucida Grande'; font-size: small;"><span class="Apple-style-span" style="font-size: 11px;"><br />
</span></span>Believe it or not, Nikita Khrushchev, one year before becoming the next USSR president after Stalin, delivered a long speech about prefabricated housing and its challenges. It was back in 1954.<br />
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<div class="separator" style="clear: both; text-align: center;"><a href="http://2.bp.blogspot.com/_PnCPTb2jz6w/TKpQmPZqOXI/AAAAAAAAAFU/RN-V2B9mUYM/s1600/khrushchev.jpg" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="295" src="http://2.bp.blogspot.com/_PnCPTb2jz6w/TKpQmPZqOXI/AAAAAAAAAFU/RN-V2B9mUYM/s400/khrushchev.jpg" width="400" /></a></div>The speech title was: <a href="http://volumeproject.org/volume/2009/00/00/Industrialised+Building+Speech%2C+1954/7783">'<i>On the extensive introduction of industrial methods, improving the quality and reducing the cost of construction</i>'</a>. The speech was given at the National Conference of Builders, Architects, and Workers in the Construction Materials on December 7, 1954.<br />
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What is this post about? A Google search took me by pure chance to the highly recommendable Dutch quarterly <a href="http://volumeproject.org/">Volume</a>, dedicated to architecture and design. The speech text is a free access article appearing on a recent issue (2009-3), named 'The block' and dedicated to mass housing. From the editorial: <br />
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<em>Housing the billions: never before were those involved in architecture and construction confronted with such a challenge. World-wide there will be housing needed for some three billion people in the coming forty years. In the Netherlands, after the post-War ‘reconstruction period’ during which dealing with ‘the big number’ was the central issue, attention shifted entirely to the individualization of design. <br />
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Here and in much of Europe we have indeed bid farewell to blueprints, repetition and uniformity, but is that farewell as definitive as we think? Is this extreme individualization sustainable? Is there not something to be learned from mass construction and the industrial production of housing such as, for example, from that which houses and provides an urban environment for 70% of Russia’s population?</em><br />
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Another accessible article is <a href="http://volumeproject.org/volume/2009/00/00/Standards%2C+Classes%2C+Formats/7794">'Standards, classes, formats'</a>, by Bart Goldhoorn, one of the main contributors to the Volume issue. This is a glimpse to its content:<br />
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<em>In architecture, to use the word “standard” seems to be a taboo. ...The experiences of the 1960s and 1970s in mass-produced architecture have apparently been so traumatic, that this has led to the creation of a dogma in architecture and urbanism that translates as diversity = good, uniformity = bad.</em><br />
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...The dogma of architectural individuality excludes from discussion a field of knowledge and experience which is essential to the development of any contemporary form of manufacturing. ...In processes of design, production and marketing the use of standards actually enables innovation and diversification. True, the nature of these standards is very different from the way they manifested themselves in the mass housing project of the 1960s. ...It is time to break the taboo and consider the application of this experience in the field of architectural design – not as an aim in itself, but as a key to make good design available to more people.</em><br />
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I also think this is a very important problem, one that should concern us as architects, and one we will have to deal with in the coming years. Now, what can we learn about the Russian race to mass housing construction of the 50s, 60s and 70s? If the Volume issue is right, we should take lessons from the mistakes of those days, and try not to repeat them.<br />
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<a href="http://1.bp.blogspot.com/_PnCPTb2jz6w/TLD-j0NsnxI/AAAAAAAAAFY/XkofYkBGCIA/s1600/Panel_Khrushchev_house_in_Tomsk.jpg" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="300" src="http://1.bp.blogspot.com/_PnCPTb2jz6w/TLD-j0NsnxI/AAAAAAAAAFY/XkofYkBGCIA/s400/Panel_Khrushchev_house_in_Tomsk.jpg" width="400" /></a>Under this light, Khrushchev's speech from 1954, delivered right at the start of the Soviet mass pre-fab housing process, is a pivotal document because it contains the key to what was going to fail later. My first impression at reading the speech has been of surprise: I could have never imagined a high rank politician of any country (not even Castro in Cuba) dealing with a technical issue with such level of detail, knowledge and, yes, passion. Later in the text Khrushchev declares himself a traded plumber in his youth, and then you start understanding what was going on there.<br />
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A visit to <a href="http://en.wikipedia.org/wiki/Nikita_Khrushchev#cite_note-cornnomore-262">Wikipedia</a> brings more interesting data: yes, young Nikita was welding pipes in Ukranian mines back in 1914. As a skilled metal worker he was exempt from conscription in the Great War. Between 1934-35 we find Khrushchev as superintendent of construction of the Moscow Metro. Faced with an already-announced opening date of November 7, 1934, Khrushchev took considerable risks in the construction and spent much of his time down in the tunnels. When the inevitable accidents did occur, they were depicted as heroic sacrifices in a great cause. The Metro did not open until May 1, 1935, but Khrushchev received the Order of Lenin for his role in its construction.<br />
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In 1950, as head of the Communist Party in the Moscow region, Khrushchev began a large-scale housing programme for Moscow. A large part of the housing was in the form of five- or six-story apartment buildings, which later became ubiquitous throughout the Soviet Union. Khrushchev had favoured the use of prefab reinforced concrete panels, greatly speeding up construction. These structures were completed at triple the construction rate of Moscow housing from 1946–50, lacked elevators and in some cases balconies. The blocks were nicknamed Khrushyovkas by the public. Almost 60 million residents of the former Soviet republics still live in these buildings today!<br />
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<a href="http://1.bp.blogspot.com/_PnCPTb2jz6w/TLFthfpkXwI/AAAAAAAAAFs/yAJM_1ud-sQ/s1600/during+constr+2.jpg" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="400" src="http://1.bp.blogspot.com/_PnCPTb2jz6w/TLFthfpkXwI/AAAAAAAAAFs/yAJM_1ud-sQ/s400/during+constr+2.jpg" width="266" /></a><br />
But in 1954, at the time of the speech, the construction of Khrushyovkas was just starting. The decision of using pre-fab instead of monolithic concrete construction had just been taken, not without pain for those who favoured the latter. Quoting from the speech:<br />
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<i>Our builders know that until recently there was debate over which of two paths we should take in construction – use of prefabricated structures or monolithic concrete. We shall not name names or reproach those workers who tried to direct our construction industry towards use of monolithic concrete. I believe these comrades now realise themselves that the position they adopted was wrong. Now, though, it’s clear to everyone, it seems, that we must proceed along the more progressive path – the path of using prefabricated reinforced-concrete structures and parts. (Applause.)</i><br />
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Further in the text Khrushchev goes against architects. He complains that standardized construction can't succeed if architects keep insisting on non-standard design. Design offices were of course a collective activity by then in the USSR, but interestingly architects had somehow managed until then (after Stalin's death, that is!) to remain loyal to their design individuality. The boss is not happy with this:<br />
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</div><div style="text-align: auto;"><i> They [architects] all agree that use of standard designs will significantly simplify and improve the quality of construction, but in practice many architects and engineers too aspire to create only their own one-off designs.<br />
Why does this happen? One of the reasons, evidently, is that there are flaws in the way we train our architects. Led on by the example of the great masters, many young architects hardly wait to cross the threshold of their architecture institutes before wanting to design nothing but unique buildings and hurrying to erect a monument to themselves. If Pushkin created for himself a monument ‘not made by human hand’, many architects feel they simply must create a ‘handmade’ monument to themselves in the form of a building constructed in accordance with a unique design. (Laughter, applause.)</i><br />
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<a href="http://2.bp.blogspot.com/_PnCPTb2jz6w/TLFtRTLwWaI/AAAAAAAAAFo/7chFTuvXRtk/s1600/during+constr+1.jpg" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="400" src="http://2.bp.blogspot.com/_PnCPTb2jz6w/TLFtRTLwWaI/AAAAAAAAAFo/7chFTuvXRtk/s400/during+constr+1.jpg" width="310" /></a><br />
Now Khrushchev goes more personal. In a purely Stalinesque style, he attacks a such comrade Mordvinov, president of the Academy of Architecture and also present at the speech (I imagine not with a very lively face at this part):<br />
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<i>If an architect wants to be in step with life, he must know and be able to employ not only architectural forms, ornaments, and various decorative elements, but also new progressive materials, reinforced-concrete structures and parts, and, above all, must be an expert in cost-saving in construction. And this is what comrade Mordvinov and many of his colleagues have been criticised for at the conference – for forgetting about the main thing, i.e. the cost of a square metre of floor area, when designing a building and for, in their fascination with unnecessary embellishment of facades, allowing a great number of superfluities.</i><br />
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It's difficult not to agree to a certain extent with the basis of this critique, if we realise that the issue under discussion was building houses by the thousands for a population that were living almost in barracks after the war end. More ammo was thrown to the audience:<br />
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<i>Certain architects have a passion for adding spires to the tops of buildings, which gives this architecture an ecclesiastical appearance. Do you like the silhouette of churches? I don’t want to argue about tastes, but for residential buildings such an appearance is unnecessary. It’s wrong to use architectural decoration to turn a modern residential building into something resembling a church or museum. This produces no extra convenience for residents and merely makes exploitation of the building more expensive and puts up its cost. And yet there are architects who fail to take this into account.</i></div><br />
Khrushchev, once convinced he had made a clear point here - several other examples are served in the conference, with numbers, unit cost comparisons and quotations - changes subject to another hot topic: improving quality of construction. It was already evident to this generation that quality would be the main issue of the housing programme in the future, one which would probably never be solved but against which a dialectic fight had to be launched from day one. Here goes our Quixote:<br />
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<a href="http://3.bp.blogspot.com/_PnCPTb2jz6w/TLD-5fencqI/AAAAAAAAAFc/uEC-zAn-wks/s1600/another+K.jpg" imageanchor="1" style="clear: left; display: inline !important; float: left; margin-bottom: 1em; margin-right: 1em; text-decoration: none;"><img border="0" height="300" src="http://3.bp.blogspot.com/_PnCPTb2jz6w/TLD-5fencqI/AAAAAAAAAFc/uEC-zAn-wks/s400/another+K.jpg" style="text-decoration: underline;" width="400" /></a><br />
<i>Recently comrades Bulganin, Mikoyan and myself had to visit many cities in the Far East, Siberia, and the Urals. We were looked after well. Which is understandable – given that we’re demanding guests and that we have the power to criticise – and in fact do even more than just criticise. So naturally they tried to ensure the best conditions for us. (Laughter, applause.) In the city of Sverdlovsk we lived in a hotel. It has to be supposed that we were given by no means the worst rooms. (Laughter.) And in this hotel we saw that the bathroom and toilet blocks were very badly built and that the quality of decorative work was poor. We asked for the hotel director and the city leaders and said to them: ‘Look how poor this work is!’<br />
The quality of the tiling was poor and it had been carelessly laid. The pipes in the toilets and bathrooms were covered in rust and had been hurriedly painted with some sort of grey paint before our arrival, with more paint being splashed onto the walls at the same time. The way that these pipes had been joined together was very bad and I, as an ex-plumber, was very indignant: even in pre-Revolutionary times pipe joints down the mine were done better and more cleanly than in this hotel in Sverdlovsk.</i><br />
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The actual <a href="http://en.wikipedia.org/wiki/Khrushchyovka">Khrushyovkas</a> designed and built after 1954, up to and during the Brezhnev era, were not precisely a model of high quality, but they were an example of pure standardization. The leader was to be followed in this point, if not in quality. In 1954-1961, engineer Vitaly Lagutenko, chief planner of Moscow, designed and tested the mass-scale, industrialized construction process, relying on concrete panel plants and a fast-track assembly schedule. In 1961, Lagutenko’s institute released the K-7 design of a prefab 5-storey that symbolised the Khrushchyovka. 64,000 units of this type were built only in Moscow from 1961 to 1968, but it was just a beginning. In Moscow, space limitations forced a switch to 9 or 12-story buildings (these with lifts) at the end of the 60s. The last 5-story Khrushyovka was completed there in 1971. The rest of USSR continued building Khrushyovkas until the fall of communism; millions of such units are now still inhabited and well past their design lifetime.<br />
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<div class="separator" style="clear: both; text-align: center;"><a href="http://4.bp.blogspot.com/_PnCPTb2jz6w/TLF4dwisf-I/AAAAAAAAAFw/ScrRQ3crVVM/s1600/floor+plan.jpg" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="352" src="http://4.bp.blogspot.com/_PnCPTb2jz6w/TLF4dwisf-I/AAAAAAAAAFw/ScrRQ3crVVM/s640/floor+plan.jpg" width="640" /></a></div><br />
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The facade units, serving both as structural and cladding panels, were made at concrete plants and trucked to the site just-in-time. Lifts were considered too costly and time consuming, and according to Soviet standards, five stories was the maximum height of a building without an elevator. Thus, almost all Khrushyovkas have five stories.<br />
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Khrushchyovkas featured combined bathrooms. Lagutenko refined the space-saving idea, replacing regular-sized bathtubs with 120 centimeter long "sitting baths". Some theorists even considered combining toilet bowl functions with the shower's sink, but the idea was discarded. Kitchens were also small, usually 6 square meters.<br />
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Typical apartments of the K-7 series have a total area of 30 m2 (1-room), 44 m2 (2-room) and 60 m2 (3-room). Not big really, but that was not their greatest defect. Construction was really bad: issues of water penetration, excessive air permeability and low acoustic insulation between apartments (due to thin internal non structural partitions) have been constant complaints among its users. The main problem though was to be the incredibly low thermal insulation, both at the concrete walls and at the metal windows. Users had to install double windows, and close balconies at those models who had that privilege. Harsh living conditions in the Russian long winters and the anonimity of the blocks, all five stories high and impossible to differenciate even between cities, gave Khrushchyovkas a bad reputation almost since day one.<br />
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</div><div>This long post should be finished in a positive way. First, citing some lessons learnt for future mass housing projects. We should care less for absolute equal repetition of the model: that is not standardization, that is Social realism in its whole crudeness. Camper shoes, Ikea furniture and Zara garments tell a different story: they are recognizable products, mass fabricated, affordable, but we want to have them. Houses could be made as well designed, mass consuming products and we would love them as well. We should care more about performance when designing and building affordable houses. In fact, because of their high compacity and relatively low % of glazed openings, housing blocks are easy to insulate and to protect from wind, air and water infiltrations. We now know how to do it, in an interesting way and within budget.</div><div><br />
</div><div><a href="http://4.bp.blogspot.com/_PnCPTb2jz6w/TLD_iwHM4GI/AAAAAAAAAFk/ALXLY6NzF04/s1600/renovated+K.jpg" imageanchor="1" style="clear: left; display: inline !important; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="288" src="http://4.bp.blogspot.com/_PnCPTb2jz6w/TLD_iwHM4GI/AAAAAAAAAFk/ALXLY6NzF04/s400/renovated+K.jpg" width="400" /></a></div><div>There is more good news coming for the old Khrushchyovkas. They can be renovated and brought back to an appealing consumer state. An article at <a href="http://www.sptimes.ru/index.php?action_id=2&story_id=5483">The St. Petersburg Times</a> in 2001 brings us the story: the lowly krushchyovka may be given a new lease of life, at least if the Danish Foundation for the Construction of Attic Apartments in Russia has its way. The foundation presented its pilot project for the reconstruction of some of St. Petersburg's most unappealing housing. The Danish foundation, aided by six Scandinavian commercial companies, has carried out a pilot reconstruction project at a block in St. Petersburg. The project, which took only nine months to complete, added a mansard for nine apartments, insulated the facades from the outside to improve heat retention, changed windows, closed balconies and renovated the building's heat plant.</div><div><br />
Now the gleaming six-story building with glassed-in balconies and fresh white paint is the envy of the neighborhood, surrounded by its decaying former twins. This project is one way of prolonging the life of these buildings for another 50 years, according to Lev Khikhlukha, who directed the program for the Russian branch of the Danish company Velux. Not bad, don't you think? And the old ex-plumber would have probably been happy with the quality - at last.</div><div><br />
An interesting book on pre-fab housing during the 20th century (not just Soviet blocks, obviously) is '<a href="http://books.google.es/books?id=5ev9rhS2sFIC&printsec=frontcover&dq=home+delivery:+fabricating+the+modern+dwelling&hl=es&ei=M2yxTJXmCoWW4gai-9SLBg&sa=X&oi=book_result&ct=result&resnum=1&ved=0CCsQ6AEwAA#v=onepage&q&f=false">Home delivery: fabricating the modern dwelling</a>' written by Barry Bergdoll and Peter Christensen and edited by the NY Museum of Modern Art. The Google book link is quite complete.</div>Ignacio Fernández Sollahttp://www.blogger.com/profile/03918193520738485621noreply@blogger.com5tag:blogger.com,1999:blog-1298203288964657974.post-89377331585987911972010-10-01T07:27:00.021+02:002010-10-10T23:56:38.793+02:00Hot spots and death rays - a burning issueThis is the news from <a href="http://www.telegraph.co.uk/news/worldnews/northamerica/usa/8031620/Gests-burned-by-death-ray-from-Las-Vegas-hotel.html">The Telegraph.co.uk</a>, yesterday morning:<br />
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<div class="separator" style="clear: both; text-align: center;"><a href="http://3.bp.blogspot.com/_PnCPTb2jz6w/TKVwKCV7mSI/AAAAAAAAAFE/2QAXCrULBoY/s1600/las-vegas-resort-7_1544641c.jpg" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="256" src="http://3.bp.blogspot.com/_PnCPTb2jz6w/TKVwKCV7mSI/AAAAAAAAAFE/2QAXCrULBoY/s400/las-vegas-resort-7_1544641c.jpg" width="400" /></a></div><b>Guests burned by 'death ray' from Las Vegas hotel</b><br />
<span class="Apple-style-span" style="-webkit-border-horizontal-spacing: 2px; -webkit-border-vertical-spacing: 2px; font-family: 'Lucida Grande'; font-size: 16px; white-space: pre;"></span>Holidaymakers at the Vdara hotel reported that their hair had been singed and that plastic bags had melted in the heat of the hotel. The hotel's owners said that the tall, concave tower collected and intensified sunshine to create what staff call a "death ray" focused on the swimming pool area.<br />
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Bill Pintas, a lawyer from Chicago staying at the hotel, said that he suffered from the heat soon after noon one day. "I'm sitting there in the chair and all of the sudden my hair and the top of my head are burning," Mr Pintas told ABC News. "I'm rubbing my head and it felt like a chemical burn. I couldn't imagine what it could be. I used to live in Miami and I've sat in the sun in Las Vegas 100 times," he said. "I know what a hot sun feels like and this was not it."<br />
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Mr Pintas also showed how the black lettering on his white plastic carrier bag had been burned through by the sun. Plastic bags are typically made of polyethylene, which melts at about 120 C.<br />
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<a href="http://1.bp.blogspot.com/_PnCPTb2jz6w/TKVx-lpvOQI/AAAAAAAAAFI/hgpZJjMaLgI/s1600/100929-deathray-03.jpg" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="320" src="http://1.bp.blogspot.com/_PnCPTb2jz6w/TKVx-lpvOQI/AAAAAAAAAFI/hgpZJjMaLgI/s320/100929-deathray-03.jpg" width="284" /></a>Gordon Absher, a spokesman for MGM Mirage, the hotel's parent company, said they were aware of the problem. "Because of the curved, concave shape of that hotel, they sometimes get isolated pockets of high temperatures," Mr Absher said. He said a film applied to the hotel's exterior had stopped 70 per cent of rays being reflected, but conceded this had not been enough.<br />
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Designers are now working to address what he called "solar convergence", he said.<br />
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Well, these are the reported news. We facade guys are aware since some time of similar situations, always located in hot areas of the world. This was up to now called a concave mirror effect, or simply hot spots, although death ray sounds much more interesting!<br />
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Why does this occur? And how to avoid it?<br />
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<b>Why does a hot spot happen?</b><br />
The reason is simple: modern glass with solar control coatings has a rather high solar energy reflectivity. Most of the radiant energy arriving from the sun to the outer glass pane gets reflected to the outside (instead of crossing the glass). This is a desired effect to avoid too much overheating inside the glazed spaces.<br />
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When the glass surface is flat or convex, the reflected radiation is dissipated onto the atmosphere. But things change when the outer glass surface is concave. Then, depending on the curvature radius, sun rays can concentrate in certain points along the day, varying with the sun position. If these points are located in the air surrounding the building, nobody will realize about them. But, if one of the concentration points (the foci of an ellipse or the center of a circle) falls in an area where there is something sensible to extra heat, then we see the consequences. There is a very clear example in Milan. Sun rays coming from the new headquarters of the Lombardia Region in Milan are overheating and deforming the PVC roller shutters of the neighbouring buildings, as shown in the image below from La Repubblica. The problem has been there since summer 2009. You can see more images at the <a href="http://milano.repubblica.it/multimedia/home/8317027/1/1">picture gallery from the newspaper</a>.<br />
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<div class="separator" style="clear: both; text-align: center;"><a href="http://3.bp.blogspot.com/_PnCPTb2jz6w/TKeQjI2WJVI/AAAAAAAAAFQ/OUZSShfPA1E/s1600/Milano.jpg" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="213" src="http://3.bp.blogspot.com/_PnCPTb2jz6w/TKeQjI2WJVI/AAAAAAAAAFQ/OUZSShfPA1E/s320/Milano.jpg" width="320" /></a></div><b>How can we measure it?</b><br />
A pyranometer is a sensor that measures broadband solar irradiance on a planar surface. What a pyranometer reads is the solar radiation flux density (in W/ m2) from a field of view of 180 degrees. If solar irradiance data in a certain area are clearly higher than the average solar radiation in the region, the pyranometer can check it and measure it. After taking a number of measurements along two-three days we come out with a 'plan of hot spots': a distribution of unexpected solar radiation values, measured in flux and in surface temperature. So, knowing if Mr Pintas, the lawyer from Chicago burned at the Vegas hotel, was right or was exagerating would take around three days work with this device.<br />
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<b>And how can we avoid it?</b><br />
This is difficult once the glass concave surface is in place, because the owner is not inclined to change the building shape at this stage. The obvious solution is to avoid concave surfaces with highly reflective glass. So, the typical way out of the fuss is to add a film onto the outer glass face that reduces the energy reflectance.<br />
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A reflective glass can have an energy reflectance value of 40%, which is really high. This is the appearance of a magnetronic or pyrolitic 'mirror glass'. Luckily architects don't favour this appearance nowadays (except in Vegas, Dubai or Shanghai, where the problem is most common). The funny thing of the building in Milan - which is not concave, but convex - is that the effect is accentuated because there are several glazed walls, all with a double skin curtain wall. The external film can reduce the reflectance to a value below 15%, which is the typical energy reflectance of a non tinted - non coated double glass unit. Values as low as 8% can be achieved. It goes without saying that energy does not disappear: if it's not reflected, it must be absorbed, heating the outer glass pane. This can have two further consequences: first, the facade becomes a heat radiator to the internal space in summer (a glazed frying pan). On the other hand, the high temperature of the outer glass, combined with some external shadow (if this exists), can break the glass unit due to 'thermal shock'.<br />
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This is a well known problem. The way to avoid it is not using annealed glass, but heat strengthed or toughened glass on the outer pane - the one with the highest heat absortion due to coatings or tints. The problem with the post-applied film is that the extreme temperature difference (between the sun-hit and the shadowed parts of a glass) increases, and it can affect the inner glass pane as well, which is usually not thermally treated. So, before applying any anti-reflective coating, our colleagues in Vegas should better do some thermal calcs, or they would get rid of hot spots at the cost of having glass breakages at the hotel rooms in the near future.<br />
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We can of course predict if a certain building shape can create hot spots or not <i>during design stage</i> (using 3D modelling tools), and then adjust the building shape or the glass reflectivity to avoid them. I would strongly recommend to do it, or we will have more lawyers coming to us in the future. The existance of "death rays" is official now...<br />
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</div>Ignacio Fernández Sollahttp://www.blogger.com/profile/03918193520738485621noreply@blogger.com3tag:blogger.com,1999:blog-1298203288964657974.post-42460257197171964522010-09-26T20:46:00.008+02:002010-09-28T20:18:37.291+02:00Introduction to Architectural Science<div class="separator" style="clear: both; text-align: center;"><a href="http://3.bp.blogspot.com/_PnCPTb2jz6w/TJ-Tv3yWuvI/AAAAAAAAAFA/_-FLmvn_YF8/s1600/Introduction_to_ARCHITECTURAL_SCIENCE.jpg" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="320" src="http://3.bp.blogspot.com/_PnCPTb2jz6w/TJ-Tv3yWuvI/AAAAAAAAAFA/_-FLmvn_YF8/s320/Introduction_to_ARCHITECTURAL_SCIENCE.jpg" width="231" /></a></div><br />
<a href="http://www.amazon.co.uk/Introduction-Architectural-Science-Sustainable-Design/dp/0750687045/ref=sr_1_1?s=books&ie=UTF8&qid=1285539004&sr=1-1">Introduction to Architectural Science</a><br />
Steven V Szokolay is an Australian architect and energy / environmental consultant who has worked in Sydney and London, and teached in Liverpool, London and finally Queensland. In this university he was the founding director of the Architectural Science Unit, as well as Head of the Department of Architecture. He is now retired.<br />
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This book is a great introduction to the facts, concepts and numbers of heat, light, sound and energy applied to architecture. The second edition from 2008 is the most recent one. The reader can be a practising designer or an undergraduate student; both will benefit from a clear presentation of facts, examples and data sheets. But the best in my opinion is how difficult issues are treated in a way that sounds as if they were being taught for the first time. Just one example: the description of glare (part 2.2.4, page 148). Szokolay aptly describes the differences between glare due to saturation and glare due to contrast, as well as discomfort vs disability glare. Another clear definition is that of daylight factor (part 2.4.2), also belonging to the lighting chapter. But probably the most useful part of the book is Part 4, Resources. Here we can find the basics of energy, renewable energy, energy use in buildings, water, waste, and sustainibility issues. Short and to the point.<br />
<br />
Szokolay has also co-authored with <span class="Apple-style-span" style="font-family: inherit;">Andris Auliciems</span><span class="Apple-style-span" style="font-family: Helvetica; font-size: 22px; font-weight: bold;"> </span>a 60 pages booklet on thermal confort. The thesis is very attractive:<span class="Apple-style-span" style="font-family: inherit;"> nowadays </span><span class="Apple-style-span" style="font-family: inherit;">lifestyles, clothing, technology in building </span><span class="Apple-style-span" style="font-family: inherit;">construction and microclimate controls have tended towards homogenizing </span><span class="Apple-style-span" style="font-family: inherit;">indoor environments to which humans are exposed. These developments may </span><span class="Apple-style-span" style="font-family: inherit;">be driven by market forces, but the result is that humans are becoming adapted </span><span class="Apple-style-span" style="font-family: inherit;">to a very narrow band of conditions. This may be a threat to our survival as species: w</span><span class="Apple-style-span" style="font-family: inherit;">ithin a changing environment, survivability is greater among the <i>adaptable</i> than the <i>adapted</i>. Which trend is being favoured by technological development and thermal design?</span><br />
<br />
<span class="Apple-style-span" style="font-family: inherit;">The booklet is available on the net. Do yourself a favour and have a look at it here: </span><span class="Apple-style-span" style="font-family: inherit;"><a href="http://www.scribd.com/doc/38209143/Plea-Note-3-Thermal-Comfort">Thermal comfort</a></span>Ignacio Fernández Sollahttp://www.blogger.com/profile/03918193520738485621noreply@blogger.com2tag:blogger.com,1999:blog-1298203288964657974.post-72122102598465223952010-09-25T22:01:00.138+02:002010-09-26T16:30:58.867+02:00Metal curtain wallsOne more example of a great old document, this time from 1955 and related to a then start-up facade system, the metal curtain walls in the United States.<br />
<br />
This time it's a book (fully available to us thanks to the 'make no evil' Google guys) with the title '<a href="http://books.google.com/books?id=_2QrAAAAYAAJ&printsec=frontcover&dq=metal+curtain+walls&hl=en&ei=oVOeTK3aM5P44Aai-bSvDg&sa=X&oi=book_result&ct=result&resnum=1&ved=0CDMQ6AEwAA#v=onepage&q&f=false">Metal curtain walls</a>'. It is a compilation of the papers and discussions presented at a conference in Washington in September 1955, organized by the Building Research Institute, then a division of the National Academy of Sciences.<br />
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<a href="http://3.bp.blogspot.com/_PnCPTb2jz6w/TJ5U5lTXs7I/AAAAAAAAAEg/c89A4XtLVX0/s1600/Metal+curtain+walls+1955.png" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="320" src="http://3.bp.blogspot.com/_PnCPTb2jz6w/TJ5U5lTXs7I/AAAAAAAAAEg/c89A4XtLVX0/s320/Metal+curtain+walls+1955.png" width="241" /></a><br />
Let's start with the obvious: this conference seems to have been a well organized event, the presenters were among the best available specialists at the time, and the response of the public was overwhelming, judging by the number of companies and experts that attended the conference. It was definitely a good time to talk about the matter. Ten years after the end of the war, and just one year after the Lever House opened at 5th Avenue, there was a lot to say and to learn about curtain walls.<br />
<br />
The presenters at the conference came from different grounds. There were architects, some big firms and some from academia. Among the former was Max Abramovitz, partner at Harrison Abramovitz in New York and responsible for the planning process of the United Nations headquarters in Manhattan between 1947 and 1952. There was also a partner from SOM, describing the firm's design method for curtain walls at the Ford Motor headquarter in Detroit. The result of an investigation from the School of Architecture at Princeton University about stainless steel curtain walls (conducted in 1954) was also presented.<br />
<br />
There were several specialists from different manufacturing companies and some other experts on thermal and acoustic issues. One presentation discussed the role of curtain wall erectors. It is surprising to see how little things have changed in this regard: the poor chaps who installed facades were experiencing the same problems and showing the same clear logic as their equals do today.<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="http://4.bp.blogspot.com/_PnCPTb2jz6w/TJ55OnvfFxI/AAAAAAAAAEk/MMzwSTsdRd8/s1600/cw-brick.png" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="640" src="http://4.bp.blogspot.com/_PnCPTb2jz6w/TJ55OnvfFxI/AAAAAAAAAEk/MMzwSTsdRd8/s640/cw-brick.png" width="398" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Poorly insulated curtain walls have a two times better U-value than non-insulated brick facades. It all depends on the comparison you select to do...</td></tr>
</tbody></table><br />
The general impression among the panelists was that curtain walls were going to be the next big thing in facades design and construction for the years to come. They were damn right. One might expect here a lot of naive comments on the advantages of the new technology. Instead, there was surprisingly very few self-praising; quite the opposite, presenters with different technical backgrounds were rather clear in assessing the many problems still unresolved for lightweight cladding.<br />
<br />
It seems that at the time architects and owners had fallen in love with glazed facades, whilst contractors and specialists seemed already worried about the limitations of the technology in terms of thermal & acoustic insulation, air tightness, water leakage, metal corrosion and coating durability. The summary of a survey on metal cladding panels, conducted that same years among owners and contractors, shows it cristal clear. Only 2.5% of building owners were dissatisfied, while 13% of contractors would not recommend using curtain walls again. See the details here below.<br />
<br />
<div class="separator" style="clear: both; text-align: center;"><a href="http://1.bp.blogspot.com/_PnCPTb2jz6w/TJ572XRggxI/AAAAAAAAAEo/5zNwUyi5jvY/s1600/Owners&contractors.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="400" src="http://1.bp.blogspot.com/_PnCPTb2jz6w/TJ572XRggxI/AAAAAAAAAEo/5zNwUyi5jvY/s400/Owners&contractors.png" width="287" /></a></div><br />
Things were bound to change in the years to come, with owners becoming less and less interested in curtain walls - but this was still 1955. The Seagram Building details were at Mies' desk by then, and Tom Wolfe had not the least idea that 25 years later he would be writing 'From Bauhaus to our house'.<br />
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<b>The architect's view</b><br />
Max Abramovitz's text is very interesting. We are literally attending to an architect's explanation of modern architecture provided to an audience of builders and manufacturers. He could be outspoken and not too academical. He started saying that the idea of curtain wall was not new, but a development of wooden skeletons and non-bearing stone veneers or other lightweight walls. He then described the factors that made curtain walls so appealing to architects. The list deserves a quotation:<br />
<ol><li><span class="Apple-style-span" style="text-decoration: underline;">The dry wall</span>, allowing facade construction to proceed even in wet and cold weather.</li>
<li><span class="Apple-style-span" style="text-decoration: underline;">Lightweight</span>, saving in construction manpower and load to support.</li>
<li><span class="Apple-style-span" style="text-decoration: underline;">Larger units</span>, thus reducing the number of joints in the facade. For him joints were an architect's headache: the less of them the better.</li>
<li><span class="Apple-style-span" style="text-decoration: underline;">Non-corrosive and fire resistant materials</span>, that is, metals. A curtain wall wasn't more fire safe then than today, but architects have always found it difficult to distinguish between fire reaction and fire resistance.</li>
<li><span class="Apple-style-span" style="text-decoration: underline;">Prefabrication</span>, very neatly expressed: 'We will get more construction for our money'.</li>
</ol><div><b>The facade contractor's view</b></div><div>My favourite presentation, though, is the one given by the erectors representative, a such Mr. Collier, president of a facade contracting company. Among many interesting things in his text, there is a lateral comment that struck my attention. Remember, we are in 1955. Weather proofing concepts such as rain screen or pressure equalization had not been identified yet, and do not appear along the conference proceedings. On the other hand, selants based on silicone had not been developed at the time. Facade joints were caulked with Thiokol at best. Mr Collier, though, was not happy with the then predominant solution of open joints in lightweight facade panels to allow for movement, with an internal air and water sealed barrier. He prefered, based on his personal experience, an externally sealed wall to prevent water to come into the building in the first place. Well, of all the predictions made in this interesting book, the preference of Mr. Collier for externally sealed facades was going to become the mainstream solution in the US, as soon as silicone became available, and lasting until today. Dow Corning was going to be more convincing to American builders and architects than the rain screen principle. </div><div><br />
</div><div>We Europeans laugh at the Americans love for sealed joints in stone or aluminium veneer facades. But apparently Americans prefered the reasoning of Mr. Collier, an entrepreneur, to that of G.K. Garden in 1963, a researcher from a Canadian building institution and the father of the open joint design in modern facades. And they still do...</div><br />
<div><br />
</div>Ignacio Fernández Sollahttp://www.blogger.com/profile/03918193520738485621noreply@blogger.com3tag:blogger.com,1999:blog-1298203288964657974.post-51642133301665097862010-09-20T21:14:00.060+02:002010-10-31T08:16:30.122+01:00The facades of the futureThis is a post under construction. In fact, it may be under construction for years, since its theme will always remain open. What are the key indicators of the facades of the future? What will matter - and what won't - in relation to how we design building envelopes today?<br />
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The following is a list (yes, I love lists) of the issues that will define facades design in the near and longer future. Let's put a time lag to this: by 2020? That's rather soon. 2030 is better: twenty years from now.<br />
<div><br />
<b>1. Image:</b><br />
a) Media facades - they tell us a changing message. See below and here for a video of Ned Kahn's <a href="http://www.youtube.com/watch?v=OWIhkvgg6MQ">facade moved by the wind</a>:<br />
<div><div><ul></ul><ol><ul></ul></ol><ol></ol><table cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/_PnCPTb2jz6w/TJfDiPlgNaI/AAAAAAAAAEY/7e0XKPxy_Ik/s1600/ned_khan.jpg" imageanchor="1" style="display: inline !important; margin-left: auto; margin-right: auto; text-align: right;"><span class="Apple-style-span" style="color: black;"><span class="Apple-style-span" style="text-decoration: none;"><span class="Apple-style-span" style="text-decoration: none;"><img border="0" height="302" src="http://2.bp.blogspot.com/_PnCPTb2jz6w/TJfDiPlgNaI/AAAAAAAAAEY/7e0XKPxy_Ik/s400/ned_khan.jpg" width="400" /></span></span></span></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span class="Apple-style-span" style="font-size: small;"><span class="Apple-style-span" style="font-size: x-small;">Ned Kahn, Technorama facade - Swiss Science Centre, Winthertu</span><span class="Apple-style-span" style="font-size: x-small;">r</span></span><br />
<span class="Apple-style-span" style="font-size: x-small;"><br />
</span><br />
<div style="text-align: left;"><table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/_PnCPTb2jz6w/TJe_dYK7cDI/AAAAAAAAAEA/-Y72nGq3bDE/s1600/Nbuilding.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><span class="Apple-style-span" style="color: black;"><span class="Apple-style-span" style="text-decoration: none;"><span class="Apple-style-span" style="text-decoration: none;"><img border="0" height="153" src="http://2.bp.blogspot.com/_PnCPTb2jz6w/TJe_dYK7cDI/AAAAAAAAAEA/-Y72nGq3bDE/s400/Nbuilding.jpg" width="400" /></span></span></span></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><div><span class="Apple-style-span" style="font-size: x-small;">N Building, Tokyo. Terada Design and Qosmo - The facade is covered in QR codes. Clic a pic of this building and you will get info of all its inhabitants in your mobile</span><span class="Apple-style-span" style="font-size: medium;">.</span></div></td></tr>
</tbody></table><div><span class="Apple-style-span" style="font-size: medium;"><br />
</span></div></div></td></tr>
</tbody></table>b) Interactive facades - we can ask them for something, and they will answer. See above and <a href="http://singularityhub.com/2010/01/18/augmented-reality-building-lets-you-see-what-people-are-tweeting-inside-video/#more-10933">here for more information</a>.<br />
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c) Dynamic facades - they will move, in order to perform better, but also in a way we will consider aesthetically pleasant - as it should be: utilitas & venustas. See below and <a href="http://www.youtube.com/watch?v=zZ47Oy6B5bA">here for the video</a>.<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/_PnCPTb2jz6w/TJfBvHsLS-I/AAAAAAAAAEI/sKBgDMnDk8Q/s1600/lamas+moviles.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><span class="Apple-style-span" style="color: black;"><span class="Apple-style-span" style="text-decoration: none;"><img border="0" height="300" src="http://1.bp.blogspot.com/_PnCPTb2jz6w/TJfBvHsLS-I/AAAAAAAAAEI/sKBgDMnDk8Q/s400/lamas+moviles.jpg" width="400" /></span></span></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span class="Apple-style-span" style="font-size: x-small;">Kiefer Technic Showroom, Giselbrecht + Partners</span><span class="Apple-style-span" style="font-family: Arial, Helvetica, sans-serif;"><span class="Apple-style-span" style="font-family: Geneva;"><span class="Apple-style-span" style="font-size: x-small;"> </span></span></span><span class="Apple-style-span" style="font-size: x-small;">- The louvers move constanty depending on the day and light conditions, and on the inner use of the rooms.</span></td></tr>
</tbody></table><b>2. Performance:</b><br />
Future facades will be extremely performant. We have almost reached the limit of tectonics nowadays (what can be done to make any element structurally resistant and stable) but we have just started to grasp the surface of the non-tectonic issues (what can be done to improve the capacity of building elements to reduce thermal transmission, reduce emissivity, limit noise transmission, avoid air and water penetrations, maximize visible light transmittance whilst blocking UV and infrared rays, etc etc).<br />
<br />
We are so behind in non-techtonic related issues that there isn't even a name for those (let me suggest one: herkonics, from 'herkos', building fence and interface in Greek)</div><div><br />
<b>3. Sustainability:</b><br />
<b></b>If a building envelope performs well in terms of energy, it should already be sustainable, right? Well, in the future that won't be enough. As long as we will achieve zero-energy buildings (by both passive and active means) other issues will become more important than what they are now. That's the case with materials carbon footprint, re-usability of elements as per the cradle to cradle mantra, water retaining and reusing, etc.<br />
<br />
<b>4. Buildability:</b><br />
<b></b>Facades will always have to be fabricated, transported and installed on site. That must be made in a more efficent way - to reduce their carbon footprint, to reduce time, to reduce costs, to reduce uncertainty and risk of malfunction. This is really difficult and will consume the 20 years period I have given for this list to become reality. Can you imagine a robotic factory? You surely can. Now try to imagine a complete robotic jobsite!<br />
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Joints and interfaces between facade elements will become even more critical in the future. Again , this is science fiction, regardless the fact that we have been dicussing it since the 50's.<br />
<br />
<b>5. Post-occupancy:</b><br />
<b></b>This involves first of all facades design that allows user comfort, adaptability and dynamic response to different needs.<br />
<br />
Second, it means that our envelopes should be easy to maintain, but really so; reducing the costs, the effort and the spill of water and consumables we need now. And easy to replace: when something breaks or underperforms, the system detects it and the substitution is done together with the cleaning... Sounds futuristic, doesn't it?<br />
<br />
And, last but not least, durable facades. This is the Holy Grial of the whole story. Sustainable in Darwinian terms means lasting. Our facades today are creationists, not evolucionists. We act like gods, but gods without the power - and our 'creatures' disappear swallowed by the harshness of the real world. Some day our building envelopes will again, as in the past, be durable. It will definitely take time: I don't care if it's more than 20 years, as long as the trend goes in that direction.</div></div></div>Ignacio Fernández Sollahttp://www.blogger.com/profile/03918193520738485621noreply@blogger.com2tag:blogger.com,1999:blog-1298203288964657974.post-60287105387549959572010-09-15T20:04:00.017+02:002010-09-26T16:32:26.016+02:00Facade - structure tolerances: the buffer zone<div class="separator" style="clear: both; text-align: center;"><a href="http://4.bp.blogspot.com/_PnCPTb2jz6w/TJEJ87r9RVI/AAAAAAAAADQ/rZzKfNSHcw8/s1600/Sin+t%C3%ADtulo.png" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" src="http://4.bp.blogspot.com/_PnCPTb2jz6w/TJEJ87r9RVI/AAAAAAAAADQ/rZzKfNSHcw8/s320/Sin+t%C3%ADtulo.png" /></a></div>A visit to the Arup central library in London is always a great experience. The other day I found this book, out of catalog and unavailable in Amazon: '<a href="http://www.amazon.ca/Interfaces-Curtain-Connections-Steel-Frames/dp/1870004787">Interfaces - Curtain wall connections to steel frames</a>'.<br />
One of the interesting sections is devoted to discussing the tolerances that a designer should always consider between the plane of the building facade and the alignment of the structural steelwork. For the purpose of this post, the main structure can be steel or concrete, and the lightweight facade can be a curtain wall or any other system.<br />
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The idea of writing about this issue comes from an architect with whom we are working these days. The project name and location aren't relevant. Our architect wanted to stick the curtain wall plane to the front plane of a steel column, with no space in between. This would surely make a nice detail as shown on a Scheme Design drawing: all flush and neat. We have had to go some length to explain something quite clear to us facade engineers, but obviously not so to architects in general. The point in discussion was the need to consider a separation between the main structure and the inner plane of a curtain wall. Why is it necessary, and how big should that space be?<br />
<br />
<b>Let's go with the why first </b><br />
The structure of a building is not built by Swiss watchmakers. For example, the edge of the steel decking is is often set out from the centre line of the steel beam. In a concrete structure, the formwork is positioned in relation to the axis of the adjacent columns. Both are not proper methods - the setting out line should be the main axis lines at each floor. The result is that dimensional variations in the positioning of beams or columns are transferred to the alignment of the edge of slab. Add movements of the formwowk (in case of concrete) and you have a wobbly line instead of a perfect vertical plan.<br />
<br />
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/_PnCPTb2jz6w/TJEny0I78TI/AAAAAAAAADY/WmXWqnIed_U/s1600/laser+.jpg" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="200" src="http://2.bp.blogspot.com/_PnCPTb2jz6w/TJEny0I78TI/AAAAAAAAADY/WmXWqnIed_U/s200/laser+.jpg" width="200" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Bosch CST Berger laser</td></tr>
</tbody></table>The same, at a much smaller scale, happens with the curtain wall or lightweight facade installation. Facade contractors use accurate positioning tools as laser beams for the setting out of their lines and brackets. The image to the left is a high quality laser level, capable of self-leveling in horizontal, vertical and plan. The reader unit can find the laser beam as far as 800m away. But its accuracy is not perfect: +/-3mm vertical misalignment every 30m. Add small mistakes when marking lines with chalk on the concrete slab, bracket positioning and profiles drilling, and there you go with a certain degree of variation.<br />
<br />
<br />
<br />
<br />
<br />
<b>Now the dimensions</b><br />
<b></b>How big should the tolerance space be? What I liked about the book above is the way the authors divide the requested space - the total tolerance - in three areas:<br />
<ol><li>Tolerances which define the zone within which the main structure should be built. Their value depend on the national building codes, the material, the quality of workmanship and the building size and shape.</li>
<li>Tolerances to absorb the misalignments of the facade elements in relation to their theoretical plane. These are smaller than the first ones, a rule of thumb is three times smaller.</li>
<li>A 'buffer zone' between the two tolerances above. This is an additional contingency against excessive dimensional errors. In practice, all structural frames exceed their specified tolerances at least in some points of the structure. </li>
</ol>The buffer is the way to avoid breaking arms and legs in order to fix a facade in every building. But remember, they are not intended to be a relaxation of the structural specification (or of the facade installation), rather they are a recognition that sometimes work does not go as planned - even in Switzerland.<br />
The drawings below show, nº 1 for steel structure + curtain wall and nº 2 for concrete structure and precast, my personal rule of thumb for a general structure - facade tolerance. The three areas are shown in each case.<br />
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/_PnCPTb2jz6w/TJE3EqM58RI/AAAAAAAAADg/wY4yRpy8jMk/s1600/1.png" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="400" src="http://3.bp.blogspot.com/_PnCPTb2jz6w/TJE3EqM58RI/AAAAAAAAADg/wY4yRpy8jMk/s400/1.png" width="395" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Steel structure plus curtain wall tolerances</td></tr>
</tbody></table><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/_PnCPTb2jz6w/TJE3yxJ0slI/AAAAAAAAADo/NNUeJXFmLmg/s1600/2.png" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="400" src="http://3.bp.blogspot.com/_PnCPTb2jz6w/TJE3yxJ0slI/AAAAAAAAADo/NNUeJXFmLmg/s400/2.png" width="395" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Concrete structure plus precast concrete cladding tolerances</td></tr>
</tbody></table><div class="separator" style="clear: both; text-align: center;"><br />
</div>The buffer must not be excessively large, since fixing details which have to trasfer the cladding loads across the zone will themselves become significant and costly structural elements. As the cladding contractor effectively carries the cost of the buffer, the designers should consult him to assess a realistic dimension, at least in special cases.<br />
<br />
You've got the point now. Let's assume this is too detailed to remember; what should be the real rule of thumb for architects? Easy: the theoretical distance between outer structure and inner wall should be 60mm for curtain walls, 70mm for precast. This is easier to keep in mind.Ignacio Fernández Sollahttp://www.blogger.com/profile/03918193520738485621noreply@blogger.com3