Wood structural materials are preferred by US homebuilders largely because (1) the US home building industry is mostly familiar with wood framing method, (2) the units of construction (i.e., studs, joists, panels, etc.) are small and easily transportable, and (3) wood-framed structures can be erected without the need for specialized tools or large equipment. Structural assemblies such as the roof, floors, and walls are generally constructed with nominal 50.8 mm (2 inch) lumber members ranging in nominal depths from 101.6 to 304.8 mm (4–12 inches) and sheathed with structural wood panels for stability and security, such as oriented strand board (OSB) or plywood. The prevailing system used for the construction of single-family homes in the USA is platform framing using light wooden dimensional lumber. The main structural assemblies are described and subsequently designed using a combination of prescriptive guidance and engineering design. In this chapter, the design of a typical light-framed home is discussed. Engineers typically become involved with design items such as foundation design, steel framing design, or engineered product specification. An owner may choose to involve the engineer to improve quality or economy of the home design.
A structural engineer can assist, if needed, with design items not within the scope of the building code or if alternative design approaches are required. Design of light-framed single-family homes is typically conducted by an architect or construction contractor using prescriptive building codes. The unit pieces of dimensional lumber are light and easily handled once on the work site. Dimensional wood lumber is readily available and due to its convenient unit dimension can be packaged neatly and transported to work sites by either commercial transport or personal vehicle. Light-wood framing construction techniques have been traditionally used in America for the construction of single-family residences.