Will trusses will be part of new American homes in the future? That question has been the reason I keep a close eye on the home built for NAHB’s International Builders Show. Since 1984, this off-site exhibit, “The New American Home” (TNAH), has presented the latest innovations in home building. For the first 20 years of TNAH, which rotated among Houston, Dallas, Las Vegas, and Atlanta, the home’s architecture reflected that of the local area, and most of America. In 10 Texas showings, for example, since D.R. Horton was one of the providers, TNAH was likely stick-framed. In five Atlanta and three Las Vegas showings, TNAH would have been trussed. Beginning in 2003, the IBS show had grown so big that only Orlando and Las Vegas could accommodate it, and starting next year, the show will be held only in Las Vegas. We should expect to see a future of flat roofs, and thus a challenge for wood truss construction. [For all photos, See See PDF or View in Full Issue.]
On the way to TNAH, riding through a neighborhood of traditional homes, I spotted an ultra-modern façade through a clearing in the lush foliage. Like the Orlando show I wrote about in March 2023, “Is the Future Flat?”, this 7600 sq ft palace was shoehorned on a relatively narrow lot between two more traditional homes. Despite the long, shallow cantilevers projecting outward, I suspected this flat-roofed edition was wood framed, like the last several, but since none of the framing would be exposed, I would have to look for other clues.
Glancing up at the roof, I wondered what roof covering was being used that could beat the heat on this large, nearly commercial-sized flat roof. Will its 1/4” per ft slope be adequate to shed the torrential Florida downpours that accompany 24” of summer rainfall? I was relieved to learn that the last six TNAHs used an engineer’s dream product: closed-cell high density polyurethane (HDPE) with an acrylic coating, like what is used to insulate interior spaces. Use of HDPE can decrease dead loads by 50%, and deflection by an equal percentage, which minimizes ponding on these long-spanning, shallow flat roofs. And, what will be even more important as TNAH moves to Las Vegas is that this HDPE has a solar reflectance index (SRI) of 73, compared with a maximum of 20 for traditional built-up tar and gravel roofs. Of course, HDPE can be of equal benefit on trusses spanning podium apartments and flat-roofed town houses.
Inside TNAH’s modernist exterior, I found the apparent need for three 30’ long, shallow beams that either support a glass wall or span above one. The stringent deflection requirement led me to question whether wood LVL members would work. But, I learned more when I saw the floor system.
As I descended a staircase to the lower level, I found an array of sports cars, but I saw no driveway out of the space. Then, I spotted a turntable built into the concrete slab, and a car elevator to raise cars to street level. The guide explained that the owner entertains large groups here and needs space for 18 vehicles. So, clearly the fire risk exceeded that of a normal residential occupancy, requiring a steel structure above this garage, perhaps necessitating steel in the rest of the structure.
Thus, construction photos revealed that light-gauge steel frames the rest of the house, plus three wide flange steel beams spanning those 30’ distances. Nevertheless, much was revealed by examining the steel construction details. Note the long steel X-bracing in the walls, which was repeated throughout the structure. I counted 75 spot welds that attach each end of each X-brace to the steel studs and tracks, which dictated off-site fabrication, which had to be excruciatingly difficult.
Due to the incredible complexity and cost of 2026 TNAH’s framing, I suspect 2027’s will be wood framed, as it was in 2025. This upcoming TNAH is being built in the same Ascaya community, perched on a shelf cut into a mountainside, overlooking the Las Vegas Strip. Compliance with Ascaya’s very strict architectural standards requires modernist designs with flat roofs, but any of the many local component manufacturers will surely be able to truss it with confidence. Stay tuned!