Many of the typically concrete medium-rise residential buildings throughout China have flat roofs that tend to leak and are poorly insulated for energy conservation and thermal comfort. These existing roofs can with advantage be covered with a pitched wood frame truss roof. This is a cost-effective way of keeping the rain out, improving the look of the building, and reducing energy costs, with additional insulation in the roof cavity. It is also an effective way of delivering a thermally comfortable attic space for extra accommodation, or to install mechanical systems for heating, cooling, and ventilation.

This system is as competitive for installing roof systems on new concrete structures as for replacing old concrete roof systems.