The sweet spot of wood component supply is high dollar, high density housing. Beneath expensive finishes are complex structures, and the opportunity to gain significant value. With advanced whole house software, CM’s are able to model the mechanical systems as an integral part of the structure (figure 1). They can demonstrate the advantage of open-webbed trusses in fully utilizing floor and roof cavities. And they can obtain more value from wall panels, in these compact, multi-story structures, than in detached housing. In summary, manufacturers of floors, roofs and walls are uniquely positioned to become the center of the building systems integration.
The appeal of tightly packed housing units is greatly ‘elevated’ by rooftop decks. These outdoor living spaces provide utility comparable to backyard space, without the associated land cost. But they often require many times the design effort. In urban settings, added loads from “green roofs” with plantings further complicate the task. Within the roof truss webbing, pipes from roof drains must be accommodated. Cupola-like roof structures and mansard details give rise to wind and snow drift load considerations.
Design of floor containers filled with mechanicals is not trivial, as shown in the accompanying truss layout (figures 2 and 3). Beams and girders supporting stair openings and upper-story-offsets complicate the task. And the popularity of balconies, often framed perpendicular to floor trusses, provides special challenges. Trusses must be precisely located, designed, and detailed.
Rising to uncommon heights, wall structures are no longer simply framed. LVL columns and multiple-stud-packs must exactly trace load paths. Taller walls exacerbate shear stresses, often requiring portal frames, especially around garage openings. Wood Smart Components are gaining acceptance as alternatives to steel shear walls (figure 4).
Component manufacturers who have embraced the challenge of high-end attached housing have not mastered their craft alone, but in concert with the entire construction team. They have relied more heavily on the Engineer of Record to specify and verify loading. They have collaborated extensively with HVAC, plumbing, and sprinkler contractors by exchanging 3D CAD viewer files with these trade partners. And they have elevated their value, taking best advantage of the evolving housing market.
Next Month:
Manufacturing Advantages of High Density Housing