Where insulated concrete form construction creates a concrete wall surrounded by insulating foam, structural insulated panels (SIPs) sandwich a layer of polystyrene foam between two layers of wood. The result is a rigid, load-bearing, well-insulated building module that can be trucked to a jobsite on a flatbed trailer like an oversized mattress.

These manufactured panels, normally four feet wide by eight feet high, can come in sizes as large as eight feet by 24 feet. Ranging in thickness from four-and-a-half inches to 12-and-a-quarter inches, the modules can be used for walls, ceilings, roofs and, on raised foundations, flooring.

On the construction site, panels are glued together with slender plywood-like splines, and two-by lumber is used as a top and bottom plate. No studs are used in the walls - the panels themselves provide the building's structural support. As a result, the panels greatly reduce the amount of lumber needed to build a house. In addition, construction is faster and less labor intensive.

Wood used on the panels comes from oriented strand board, a plywood-like engineered wood product made of renewable, controlled-growth wood. The wooden skin is bonded to a core of expanded polystyrene, high-performance rigid insulation to create a panel strong enough to resist loads caused by winds, snow, and seismic activity.

When glued and fastened together, the panels form a shell of virtually solid insulation, without the breaks and voids caused by building with studs. Since these breaks are normally where energy leaks occur, homes build this way are extremely energy efficient and quiet.

Manufacturing of the raw materials needed for SIPs uses little energy, and the panels do not contain urea formaldehyde, cluorofluorocarbons (CFCs), or hydrocluorofluorocarbons (HCFCs).

For more information on insulated panel building systems, contact R-Control Building Systems at 1-800-255-0176 or visit their web site at www.r-control.com.