While cool roofing isn’t new, interest in energy savings has resulted in changes in building code requirements, particularly in the southern United States, where energy use for cooling occupied space is far greater than heating costs, according to an article from Building Operating Management on the FacilitiesNet website.
In fact, use of cool roofing materials during the last two decades has spread to all climate zones in the United States, reaping varying levels of energy savings.
Roofing can be made cool via a membrane, a reflective coating, or — in the case of steeper roof slopes — reflective shingle and tile products.
The aim of cool roofing is to achieve both high albedo and high emissivity. Albedo measures the extent to which a roofing material reflects solar light, thereby helping mitigate unwanted heat gain. Emissivity is the ability to release heat absorbed from infrared solar energy.