Stick building energy-efficient exterior walls may be simplified with Nascor Systems. This company makes interlocking columns, panels, cripples, and splines that can be assembled on site to build pre-insulated, structural walls. The components can be fit together to accept any configuration of window and door openings. They are then nailed to 2x6 or 2x8 plates, and tipped up like conventionally framed walls. The 5-1/2- and 7-1/4-inch walls boast ratings of R-20 and R-30, respectively. The high R-values are reportedly due to the thermal break provided by sandwiching expanded polystyrene (non-CFC-foamed) between flatframed wood studs. Thermal bridging occurs only at the top and bottom plates. Using a specified sealant and taping the joints between each component, the manufacturer claims the walls meet Canadian
