With the high insulation value and low infiltration, a SIP home can be cooled or heated with much smaller heating, ventilating, and air-conditioning (HVAC) equipment and much less energy consequently, the homeowner's energy each month will be much less. The SIP home costs about 5 to 10 percent more initially, but additional savings quickly offset this extra cost in energy bills. Studies have shown that building with SIPs can result in homes that are up to 60 percent more efficient than site built homes of comparable size. Wall panels can deliver R-values of R-14 to R-24 and roof R-values of up to R-41 or more, depending on the thickness of the foam core and the manufacturer's system of fabrication. See http://www.sips.org/ for additional information.