Workshop talks given at Southern California Edison

James Carpenter

James Carpenter is a sculptor and principal of James Carpenter Design Associates in New York, New York. As an artist, he is considered to be a foremost innovator in materials technologies. For more than 30 years, his work has focused on the exploration of light as a means to bring form to structure and reveal the environment. Mr. Carpenter has worked collaboratively with major architects in the U.S. and abroad on significant building projects. A recognized expert in glass technology and materials, Mr. Carpenter has consulted with glass companies such as Corning, Pilkington, and Schott. He is a graduate of the Rhode Island School of Design and an adjunct professor teaching structures at the University of Pennsylvania. http://www.jcdainc.com/

The discussion this morning was quite interesting in terms of bringing people together from around the world that share an interest in the development of glass wall systems. Their focus has of course been on the predominant European development of double wall façade systems. The following speakers, Matthias Schuler and Erin McConahey from Ove Arup will be speaking on more technical issues and I thought that my role today, somewhat prompted by Eleanor Lee's comments this morning about "Is this whole drive for double walls really simply a fashion or is there an underlying desire to seek performance out of these walls and the understanding of what is driving the motivation for these walls?" I thought that I would talk about this issue of fashion or function, rather than undertake case studies of buildings. It would be important today to talk about these façade developments because it is extremely critical as to why these things are happening in our time, meaning over the last ten years. Historically, I think that we have to remember the very earliest double wall systems came from this country. Specifically, the Hooker Chemical Building in Niagara, NY was a very early example of an extremely deep wall system with internal blinds that existed as a lone example of double wall construction for many years. It is a very elegant building, certainly a generation ahead of its time. That building, in fact, has served as an example to many people in Europe as the potential model upon which to pursue these more environmentally focused initiatives of double-wall construction.

Coming back to the specific issue of fashion, it is a word that trivializes the effort being expended in this area by serious architects, but certainly, as with any change in a fundamental approach to building, less sincere practitioners will exploit only the visual characteristics and not environmental or cultural aspects. I think that it is more than fashion driving façade development today. Industry, over the last ten to fifteen years, starting with the low-E work done in Scandinavia and the eventual sort of rise to acceptance in this country through LBNL's, Southwall's, and the efforts of other manufacturers, have improved the performance of glass coatings to the point where we are very comfortable entertaining large areas of glass façades. This trend is a rejection of much work in the 70's, which relied heavily on heat reflective coatings or heat absorptive glasses, to answer solar issues. There is currently a rejection of the methods of construction of those decades and one now sees the reemergence of modernism and its entendant embrace of transparency. It is a rejection of post modernism and a reemergence and a reinterpretation of modernism. That is not so much a fashion as much as a philosophical and aesthetic undertaking that re-states philosophical arguments that were very much in the forefront of societal discussion at the turn of the last century. That discussion focused upon the openness of buildings to enhance interchange of the individual with the public and how urban environments can be more open and communicative in terms of their functions. I think what is really driving this is a coupling of industry developments and a reemergence of a more social agenda, an agenda that attaches a significant value to the energy used being part and parcel of that social agenda.

Bicton Conservatory, England. 

Of the slides I have with me, I tried to cobble together a talk that might reflect some of these concepts. Obviously let's start with one of these earlier images - an image that we are all probably quite familiar with: the Bicton Conservatory in England which in the late 1840s represented one of the most extraordinary examples of glass structure and transparency in architecture. Comparing that building of 150 years ago to a very current building, the Peter Zumptor building in Bergenz, Austria, which is, in fact, a double wall construction but the double wall construction is different from the type of wall we have been discussing this morning. We have been talking about double wall systems, where you have cladding systems on a building and how you can control large-scale office environments with double wall construction. But this example is a pursuit of the double wall purely for an aesthetic goal and then underlying that is the energy issue. But, I think that this idea of working with glazing and information is part and parcel of this desire to pursue double wall cladding. In the double walls, we refer to them as screen walls or image walls or information walls, however those layers of information are presented to us and however they happen to be performing thermally, they are an enrichment of our day-to-day environment by the superimposition of these reflected images and how we both look out through these glass systems and how those glass systems inform our environment of both the urban environment as well as the green space environment.

Library Museum with ceramic fritting by Herzog/ deMeuron. 

This is a Herzog / de Meuron project, which uses ceramic fritting. We are all familiar with an effort to reduce the light transmission of the glass itself, but in this case they are using the fritting pattern not as some abstract dot pattern, or linear pattern but they are quite literally imposing images of a collection (this is actually a library museum) and they have basically taken elements from the collection itself and imposed them on the surface of the building so it becomes a way of combining an informational role in terms of the building as well as its weatherproofing and it's enclosure for environmental performance simultaneously.

So I think there is this other level of thinking about double walls that we did not get into today as much as we might have, which is this drive for pursuing and exploring transparency and luminosity as a means to communicate the buildings' function which is something that has been lost in much architecture in recent years. The communication often is relied on in more historical attitudes or styles, where now I think we are re-embracing a modernist idea where you can let the building speak to the complexities of image and information that we are surrounded with through all different media.

This is an unusual building that is built out of regulet glass. These are structural glass "C" channels used predominately for industrial buildings. In this case, these regulet elements and the main office part of the building sleeve each other to form a double wall construction for the insulative characteristics.

This question of whether it is fashion, aesthetic, or purely thermal performance has to do with the rationalization of the cost for these systems. If they are seen exclusively as a mechanical device to improve performance, it is, as we all know, an almost impossible task to justify these walls financially over a short period of time. It takes a very, very long period of time for these systems to pay back their initial cost. However, if the design is coupled with a stronger position of the aesthetic and how it is operating in a broader social way, I think that the payback is a secondary question rather than a primary question. In order for us to explore these walls in this country, there will always have to be a broader base upon which to justify cost. We are never going to be able to make the case with our energy being so cheap that these systems can pay themselves back in any sort of a short time frame.

Bank in Berlin. 

A subject brought up in this morning's session that is really critical in terms of thinking about these systems is that we are often thinking that double walls always need to be new buildings. Quite the opposite. I think that there are some extraordinary opportunities for using double wall systems in the recladding of existing buildings, whether it is a historical building like this example, which is a bank in Berlin, and improving its thermal performance, or whether it is recladding an existing building. An example of this is a 50's building shown here in LA or some very successfully reclad buildings in Germany. One example in Dusseldorf, which is the Stadtsparkasse building that was done by Christoph Ingenhoven, takes a 1960's building, strips the entire building down, reclads it with a double wall system and remakes the building. The building has become an entirely new structure with vastly improved thermal and daylighting performance and an entirely new, contemporary image. The client was able to reuse the frame of the existing building of a height that would never be allowed again in that particular location; if it was to be torn down and rebuilt, they would never be able to regain that original height. They were able to turn it into an entirely new space. These recladding ideas are potentially more significant than new construction opportunities and there may be another avenue for analyzing these double walls in the area of a reconstruction.

Kunsthalle, Bregenz, Austria by Peter Zumptor. 

This is a building that most of you architects would certainly be familiar with: the Kunsthalle in Bregenz, Austria, a building by Peter Zumptor. A very simple idea, a concrete frame building very carefully made on the inside with the exterior of the building wrapped around this internal frame. The circulation for the building is inserted into the cavity between the layered or lapped glass skin and the concrete frame of the building. One sees the people walk up through and behind this skin, all the circulation is around the perimeter and you proceed into the exhibition spaces, inside the building. A very remarkable object that is a perfect cube, a cube of ice that sits on the lake in Bregenz and the construction of it is such that there are very large lights and they are lapped in both directions, meaning lapped both horizontally and vertically, the intent here is that the skin is again providing a simple thermal buffer between the exterior climate and the interior climate. There is obviously a great deal of ventilation going through the lapping of the glass panels, as well as venting at the top.

Again, in an animated way, this building activates itself within its urban environment by allowing for the presence of the visitors to be visible on the exterior of the building. In the evening, when it is all lit up and you have people moving through it, the building becomes an extraordinary lively object and I think this idea of reinforcing the participation of the building in it's urban environment rather than isolate itself from the urban environment.

Refractive glass wall, First Bank Place, Hawaii, James Carpenter Design Associates. 

This image of an older project that we had done is in Hawaii. It is a wall for a building by KPF and it was a double wall building that was meant to translate light to the interior of the building, yet control the intensity of that light. Most of the images that I have been showing you have a double wall that affects its exterior presence. I wanted to show an example of how these types of structures could change the nature of light in the interior of the building. In this case, the clear outer skin forms a cavity, basically, that butts up against a translucent layer of glass that is bisected by a series of large prisms of glass that are the structure of the wall. These prisms transmit or project the daylight through the translucent glass walls to the interior. On the interior of the building, you experience a remarkable play of light while at the same time reducing the amount of heat that gets into the building itself. This is an example of how the double wall system or screen systems can work. Obviously, most of the buildings in Hawaii use very heavily coated glass from the 70's and 80's or a highly absorptive glass that appears opaque, creating an entire urban environment that is visually mute. You can't see into any one of the buildings in Honolulu and we were after just the reverse of that. Using the most transparent glass possible so that you look into the building and celebrate the unique qualities of light, visually opening the building to the public, engaging them with the internal workings of the building.

Essen, Christoph Ingenhoven.

Another example of a building constructed several years ago was designed by Christoph Ingenhoven in Essen. It is an example of the earlier types of these buildings and it prompted a lot of international attention focused on these double-wall systems. When you see this building in reality, it is extraordinarily small and has a very complex double wall system done by Gartner. This building serves as a touch point for many people in terms of double wall construction; an example of what might be done and how incredibly excessive this undertaking was. This is a building represents an extraordinary investment made on the exterior of the building for daylighting and energy conservation purposes; simultaneously this building, with a very, very small floor plate, has a fully-functioning mechanical system in it that would allow it to be operated with any type of curtain wall on it, including a conventional monolithic glass wall. It is a building that has a redundancy of systems and an extraordinarily small amount of floor area. It is an example of wonderful work spaces and provides this small town with an extraordinary urban identity, which is quite significant. That, of course, is one of the roles that these buildings have always played - that they serve as either a corporate or municipal role, communicating a unique, highly tuned agenda or identification for that company or that particular municipality.

This is the German Foreign Ministry Office in Berlin, a project we designed with Müller/Reimann Architects and with Matthias Schuler of TRANSSOLAR. We were involved in the curtainwall and roof of this building. It is a double wall system on a very different scale. The individual offices look into the atrium and then wrap around the exterior of the building. The windows are all operable but the additional layer of glass floats on the outside of the building and is there for both safety and security, as well as providing a buffer climate for the operable windows. So a double wall does not necessarily have to be full a cladding system. They can also function on a very small individual scale.

This last image is a way of using a double wall enclosure to allow for expressing a type of building that reads as a wood structure. The glass skin, providing the primary weather protection, allows for a reading of a luminous warm wood, inviting through this transparent skin. This is a goal that many architects are after. There is a desire for an enrichment of the urban and interior environments reaching out and communicating a message of interconnection with the environment, an engagement with our culture and daily experience. The initiative to pursue the double wall systems supercedes merely a fashion. Rather, it restates the architect's responsible role in advocating a transformation in our built environment and our cultural well-being.

Question/Information: eslee@lbl.gov