What’s Behind the Next Curtainwall?
It is likely that in the near future, changes in energy codes will alter curtainwall designs more significantly that any aesthetic trend architects can come up with. Up until now, many developers, and some owners, have let the higher first costs associated with better thermal performance deter them, choosing instead cheap, poorly performing wall systems, despite the fact that better envelope performance would permit them to drastically downsize their mechanical systems.
But poorly performing curtainwall may be on the way out. Codes are moving toward higher average U-values for wall assemblies, and the proportion of glass to opaque materials will likely be limited one day. That may make buildings that look like grid-paper-in-glass much more unusual than buildings like Toren.
Even Dubai, United Arab Emirates, recently announced that it had revised its building code to limit the amount of permissible window area to 60 percent. The change will take effect in 2014. If the idea of limiting the amount of glass in walls catches on, architects will have some new variables to help them justify more creative geometries as well as systems that perform better.
SOM partner Roger Duffy, FAIA, Toren’s designer, sums up the delicate balance. “In the design of curtainwalls, lots of variables must be balanced relative to a set of objectives: energy conservation, comfort, formal qualities, cost. This is both a science and an art, as unique contexts and programs create the potential for envelope solutions tuned to a responsive design idea.”