Olso Opera House Snøhetta Kirsten Flagstrads Plass 1, Olso, Norway
Cool roofs have surfaces that reflect sunlight and emit or discharge heat efficiently, keeping them cooler on sunny days. The two surface properties that determine a roof’s temperature are solar reflectance and thermal emittance, which range on a scale from 0 to 1. The larger the two values are, the cooler the roof will be.
Make the roof surface a light color and chose a roofing material that has a surface:
Solar Reflectance (SR) of > 0.7; and
Thermal Emittance (TE) of > 0.75.
In hot climates, cool roofs can help mitigate urban heat islands, reflect solar radiation back to space, and keep indoor spaces comfortable.