APA, the Southern Pine Council and the USDA Forest Products Laboratory Advanced Housing Research Center partnered together in 2001 to build a 2,300 square-foot demonstration home on the grounds of the Forest Products Laboratory in Madison, Wisconsin. This four-bedroom, three-bath house showcases moisture-resistant building practices, the latest in energy-efficient appliances and HVAC systems, and “green building” technologies advocated by the leading building science experts.


Construction began with a permanent wood foundation or PWF. Simply described, a PWF is an engineered foundation system which has a treated lumber-framed wall, sheathed with treated plywood. All lumber and plywood is pressure-treated to a retention level of .60 lbs./cu. ft in accordance with AWPA Standard C22.

PWFs have numerous advantages. They can be installed in any type of weather condition, eliminating extra labor and shortening construction time. PWFs enhance design flexibility, too, and offer easy access to wiring and plumbing.


Southern Pine, the strongest structural lumber species for engineered and framing applications, is prominently featured throughout the home. Southern Pine finger-jointed lumber was used for the wall studs, and machine stress rated (MSR) lumber was used for the engineered roof trusses. Other engineered wood products featured in the home include Southern Pine glued-laminated beams and wood I-joists. This view shows framing above the great room.


The distinctive roofline of the home was achieved using engineered trusses, built of 2×4 and 2×6 Southern Pine machine stress rated (MSR) lumber. Trusses simplified construction of the vaulted ceiling in the master bedroom, and reduced overall construction time. The open-web design of a truss expedited installation of HVAC, plumbing and electrical systems, too.


Living areas of the first floor include some 320 square feet of 1×4 Southern Pine flooring, C grade, finished with three coats of a clear polyurethane. Properly installed and cared for, Southern Pine flooring meets the challenges of the most demanding applications.


(Rear view) An extensive study of the performance of exterior treatments is underway at the home. The eastern or front side of the house features brick, the garage side is stucco, the rear or western exposure is APA Rated panel sheathing and the south side is APA Rated lap siding. FPL researchers wanted to expose various siding treatments to the elements and measure how much, if any, moisture penetrates the surface when proper flashing and sealant techniques are used consistently throughout the building.

SFPA is a nonprofit trade association that has represented manufacturers of Southern Pine lumber since 1915. Today, SFPA is the leading source of information about Southern Pine products for design-build professionals and consumers.