Benefits of the International Residential Code's Maximum Solar heat Gain Coefficient Requirement for Windows

Abstract

Texas adopted in its residential building energy code a maximum 0.40 solar heat gain coefficient (SHGC) for fenestration (e.g., windows, glazed doors and skylights)-a critical driver of cooling energy use, comfort and peak demand. An analysis of the expected costs and benefits of low solar heat gain glazing, and specifically the SHGC requirement in the new Texas Residential Building Energy Code,1 shows that the 0.40 SHGC requirement is ideal for Texas and that the benefits far outweigh the expected costs. For consumers, the requirement will increase comfort and reduce their cost of home ownership. The anticipated public benefits are also substantial - the result of full implementation can be expected to: 1) Reduce cumulative statewide cooling energy use over ten years by 15 billion kWh; 2) Reduce cumulative statewide electric peak demand over ten years by over 1200 MW; 3) Result in cooling cost savings of more than a billion dollars; and 4) Reduce cumulative statewide key air pollutants.