Why haven't double-skinned glass walls achieved the popularity in the United States that they have in Europe? This was the question asked in several different ways by audience members after the presentation on the subject by William Braham and Ali Malkawi, both associate professors in the Department of Architecture at the University of Pennsylvania in Philadelphia, at the AIA annual convention in Las Vegas last week.

The response was very practical: Energy costs. But it was also conceded that cultural issues have played a role in this as well.

After all, Braham pointed out in his presentation, the concept of double-skinned walls had been very popular in the United States in its early stages.

The presentation was titled Active Glass Walls: A Technical and Historical Account. It was both-technical and historical.

Le Histoire
Le Corbusier is credited with constructing the first double-skinned structure in 1912, a house in the Alps. Not much of significance happened after that until the Loomis house was built in Tuxedo, N.Y. in the 1950s. Then the movement gained strength in Scandinavia in the 1960s and 1970s.

Next came the energy supply crisis of the 1970s and 1980s, which morphed into the popularity of double-skinned buildings in Europe in the 1990s.

As Braham pointed out, one of the things that makes glass walls so interesting is that they make visible the interaction of the building and its environment.

Technically Speaking
The point of double-skinned walls is the desire to build glass structures that can control the climate so that it is comfortable for the occupants.

While this type of construction has become popular in Europe, the speakers pointed out, there has not really been that much research done on how effectively these skins fulfill the expectations that owners/architects have for them. (Malkawi made the point that there has been resistance in Europe to going back to the buildings to determine how effectively they are operating.)

This is where the work at the University of Pennsylvania comes in. The Building Simulation Group is trying to "take it to the next level," as the speakers phrased it, by doing research to find out what the variables are with this type of wall and to develop computer models to show how it performs.

Malkawi gave examples of such on-going work being done on Levine Hall, which is on the school's campus and constructed in 2003.

The complete papers will be posted on the school's website at www.gsfa.upenn.edu\bsg.

The AIA educational program covers a wide range of topics, as would be expected, as architects are involved in an array of activities, techniques and materials. The presentation on double-skinned walls served the purpose of increasing the knowledge a crowd of 150 people has about an increasingly popular architectural design that utilizes a lot of glass effectively, and seems poised to make a comeback in the United States.