Are Cool Roofs Green? The Answer’s Not Black and White

Cool roofs—those with reflectance and emissivity that make them good at keeping out the sun’s heat—are recommended widely without much regard for climate or project specifics. They’ve been adopted into multiple energy codes, including ASHRAE 90.1, the International Energy Conservation Code, and California’s Title 24, not to mention LEED. The concept even has its own bill in the U.S. Senate, the Energy-Efficient Cool Roofs Jobs Act (S. 2388). 

But it turns out that, beneath one of the least controversial green building recommendations, a debate is raging, with some roofing companies and architects having doubts about the extent to which cool roofs are truly beneficial.