Minimum Requirements for Roofing Material

This document sets out the minimum requirements for roofing material used as part of the Million Cool Roof Challenge. If you have any questions regarding the minimum requirements please contact team@coolroofschallenge.org.


Minimum Requirements of the Product

Any roofing material is eligible as long as it meets the following requirements:

Minimum Product Performance (Values for Reflectivity and Emissivity)

  • Solar reflectance (SR) equal to or greater than 0.70

  • Thermal emittance (TE) equal to or greater than 0.75

All products must be tested by a nationally recognised laboratory or equivalent*. Authentic testing report or label clearly stating the procedure used for testing shall be documented. KCEP may collect random sample of the product for testing to check performance.

* Examples of such processes exist within the Cool Roof Rating Council (U.S.), South African Bureau of Standards (RSA), ASTM (U.S.), JSTM (Japan), European Cool Roofs Council (EU), MOHURD (China) Recommended testing standards to be certified by the laboratory testing:

  • ASTM C1549: Standard Test Method for determination of Solar Reflectance near ambient temperature using a portable solar reflectometer

  • ASTM C1371: Standard Test Method for determination of Emittance of Materials near Room Temperature using portable emissometer

If you have a product that has not been tested by a nationally recognised laboratory, you will need to organise for your product to be tested before submitting an application with the required test report.  Recognised laboratories are often housed at universities, technical institutions, national standards agencies, or affiliated with industry trade associations.

If you are unable to get your product tested to the above standards but would still like to apply for the Million Cool Roof Challenge, we advise you to contact a recognised manufacturer. Below are some examples of manufacturers who you can contact, but this is not an exhaustive list of all manufacturers. If you have any questions or wish to discuss options, please contact the Global Cool Cities Alliance (kurt@globalcoolcities.org)

Topps Products - Manufacturer (based in the United States) of a number of cool roof coatings product lines.

Sika Corporation - Manufacturer (based in Switzerland) of commercial cool roof membranes and coatings

GAF Corporation - Manufacturer (based in the United States) of residential and commercial cool roof products