Field Notes Fall/Winter 2022January 13th, 2023 | Category: Architects' Guide to Glass and Metal
The Design Challenge Before Us
By Chuck Knickerbocker
I’ve worked on a couple of Skidmore, Owings & Merrill (SOM) projects with Keith Boswell, technical partner of SOM’s San Francisco office. In 2013, he codified his design expertise into a book, “Exterior Buildings Enclosures: Design Process and Composition for Innovative Facades.” It’s an excellent resource for the design factors that go into exterior walls on buildings of any
size, regardless of the degree of simplicity or complexity. It ought to be on every architect’s or wall system designer’s shelf.
On first read, I was captivated by the following quote, given that we (by we, I mean owners, designers, sub- and general contractors and material suppliers) are all trying to achieve carbon-neutral buildings:
“There is reliable empirical climate data to evaluate seasonal variations in solar, temperature…, humidity, and air movement/wind… Excellent lessons can be learned by studying indigenous architecture and buildings…. Indigenous architecture provides valuable clues, lessons, and real-life solutions to… building enclosure concepts and systems that have provided shelter for generations.” (Boswell, 2013)
It’s that last sentence that grabbed me. How do we incorporate those concepts into our buildings and, of particular interest to me, in the facades of those buildings?
I was involved in a re-clad project a few years ago on a building in Houston. The building, designed by Los Angeles-based architect Welton Becket, was notable for its six-footwide sunshades on every floor. Those sunshades were not only wide, but they were also strong. When the marble columns were reclad with painted aluminum panels, all the work was done while standing on them.
The orientation of the building was also interesting. The long axis of the rectangular runs from Southeast to Northwest, so one of the long elevations faces Southwest. But those sunshades reduced the amount of solar heat gain considerably through the ¼-inch monolithic glass (this was built in the early 60s). It took advantage of an age-old strategy you see in southern architecture: wrap the building with a porch to keep the sun off the façade as much as possible.
In the southwest, indigenous people taught early settlers that thick, mass adobe helps retain (in winters) and retard (in summers) heat gain in most buildings. However, it’s highly unlikely that any owner or architect will build a 40-story office building with adobe in downtown Phoenix, for example. And that, for me, is the dilemma of trying to build with indigenous architecture: how do you incorporate the ideas with modern materials. Can we shade the façade? Can we orient the building such that the effects of sun and temperature are somewhat mitigated?
The Mideast is full of examples, especially early skyscrapers, where exterior screens keep the sun off buildings. Improvements in HVAC systems and glass technology have lessened the implementation of those design types, but they work.
Further, sheltering northern exposures, primarily from wind, can help buildings in northern climes. But then that means more opaque construction, usually, which means less glass and less daylight to those spaces adjacent to it.
Another design change would be the use of balconies connected directly to a building’s structure without a thermal break of some sort between the interior and exterior.
In school, I had a passive solar energy design class. We looked at many different strategies and design concepts: Trombe walls, where solar energy could heat up floors or mass walls and then re-radiate into occupied spaces, and Earth-covered homes and buildings to moderate the effects of the sun. I drew the assignment to design for a house in Hawaii. I put it on four-foot stilts, opened the façade up with swing doors everywhere to let the blowing wind cool it off.
And with all that, it’s highly unlikely much from that design could be applied to a tall building or even a mid-level office tower, due to cost and/or allowing the occupant to control how and when the facades were to be utilized. Automating would be the way to go now, but it wasn’t commonplace back then.
The design community must bear the burden of building with more indigenous architecture in mind. But it’s also up to manufacturers to develop products that help realize these design strategies. The glazing industry’s efforts to offer more energy-efficient glass and wall systems can help. But there’s more to be done—by everyone involved in the construction industry.
How much building design will change in response to ever-increasing energy and carbon-neutral requirements remains to be seen. There’s nothing like a challenge to make all of us rise to it. I, for one, am looking forward to it. I trust you are, too.
Chuck Knickerbocker is the curtainwall manager for Technical Glass Products (TGP), a supplier of fire-rated glass and framing systems, along with specialty architectural glazing products. With more than 35 years of curtainwall experience, he has worked with numerous architects, building owners and subcontractors from development of schematic design through
installation. He can be contacted via email at charles.
To view the laid-in version of this article in our digital edition, CLICK HERE.