Trusses of the future will be flat, or nearly flat, based on The New American Homes (TNAH) that have been shown annually at the International Builders Show (IBS). Though the elegant designs of these homes may seem atypical, they have to abide by the same factors that affect every house being built, most notably the cost of land. But several other factors are worth reviewing on the 2022 TNAH, especially those that affect its wood structure. [For photos, see PDF or View in Full Issue.]
The 2022 TNAH was built in a zero-lot-line, densely packed Orlando, Florida community. But, in contrast to its neighbors, a large rooftop living area is provided in lieu of backyard space. And 2022’s mostly open space is considerably larger and more elaborate than 2021’s covered space. Both were built on top of trusses spanning interior living spaces and both illustrate the superiority of open webbed wood trusses to support rooftop living areas.
Many design features of the 2022 TNAH, like roof top living, are now widely used, especially in townhouses like these. Triple single-hung windows and triple patio doors mimic the walls of windows and the multi-slide patio doors of the model. Interior spaces are opened up by raising beams up into the structure. Spaciousness is enhanced by raising ceilings to a height of 9 or even 10 ft. and raising interior and exterior openings in tandem. Higher flat ceilings seem to be taking precedence over sloping ceilings.
Where wood trusses really shine is in their ability to accommodate the large array of water, gas, and HVAC lines coursing through floor and roof cavities. Since all these lines are flexible, the open webbing of trusses enables them to be run the shortest route, often diagonally, to reach fixtures. And this advantage is compounded with the increased use of plumbing and natural gas manifolds, which multiply the number of supply lines. In such systems, each fixture has a dedicated line that connects back to the manifold, eliminating many fittings and potential sources of leaks.
Besides the desire for outdoor living space, building height restrictions are another factor which has driven the trend to flatter roofs. For example, when complying with the 35 ft. residential height limit in Fairfax, Virginia, much more living space is provided in flat roofed structures. And in large monolithic apartment buildings, low sloping roofs are the only feasible alternative.
For nearly a decade, the IBS Show Houses have been designed with a nearly flat roof, and the 2023 house will be no exception. Fortunately, trusses continue to be an integral part of these designs and have considerable benefit in their accommodation of mechanical and HVAC systems. As the flat roof designs of The New American Homes continue to proliferate, perhaps they will influence the selection of truss assembly equipment. For a CM with a steady diet of such product, does it make sense to waste shop space by using 14 ft. wide tables? It seems that reverting to the 8 or 10 ft. wide tables would be more efficient in the long run.