Solar Reflectivity (SR)?
Solar reflectivity or reflectance (SR) is the ability of a material to reflect solar energy from its surface back into the atmosphere. The SR value is a number from 0 to 1.0. A value of 0 indicates that the material absorbs all solar energy and a value of 1.0 indicates it is all reflected. Energy Star requires SR testing of both new and aged roof products. New products must have an SR value of 0.25 or higher for steep slope (above 2:12) roofing and an SR value of 0.65 or higher for low slope (2:12 or less) roofing. Aged testing takes 3 years to complete, so not all products that meet the initial requirements are qualified. For more information, please go to www.energystar.gov.
Solar Reflectance Index (SRI)?
The SRI is used to determine compliance with LEED requirements and is calculated according to ASTM E 1980 using values for reflectance and emissivity. Emissivity is a material's ability to release absorbed energy. To meet LEED requirements, a roofing material must have an SRI of 29 or higher for steep slope (above 2:12) roofing and an SRI value of 78 or higher for low slope (2:12 or less) roofing. For more information, please go