"Energy efficient R-values of 4.3 deg/cm2 for 200mm thick walls and 5.75 for 250mm thick walls, have homeowners happy with minimal energy required to achieve a comfortable healthy home. "Environmental" cornerstone polystyrene wall system, doesn't rot or break down. There are no CFC's or HCFC's used in the processing of polystyrene. The ratio of 2% matter and 98% air, is up the scale environmentally. "Structural" The reinforced concrete posts and beams form the framework and polystyrene protects this concrete structure absorbing any shock from earthquake or winds. "Cost Effective" The speedy process of placing large panels makes it cost effective, dealing with several processes together. "Fire Safety" Cornerstone tests at BRANZ performed well. Gasses omitted from burning of polystyrene are less harmful than those given off, burning white pine.