The Cool Roof Rating Council (CRRC) announced the release of the 2025 edition of the ANSI/CRRC S100 standard (formerly the CRRC-1 Standard), which received approval from the American National Standards Institute (ANSI) on December 5, 2024. The publication of the ANSI/CRRC S100-2025 is the culmination of a process that began in June 2023, which was conducted in accordance with ANSI and CRRC requirements for the development of consensus standards.

The major changes to the ANSI/CRRC S100 standard include the addition of testing and weathering requirements for exterior wall materials, new provisions for polymer and composite roofing materials, and the introduction of the protocol for liquid-applied coatings on rough substrates that was adopted into the CRRC-1 Roof Program in 2021. The revisions derived from the CRRC and ballot comments that were evaluated by the CRRC Consensus Body, a balanced group of stakeholders representing diverse interests. After two rounds of public review, the draft standard was approved by the Consensus Body, CRRC Board of Directors, and ANSI.

The ANSI/CRRC S100 standard is an American National Standard that provides a consistent reference in building energy codes and voluntary green building programs—such as the International Energy Conservation Code (IECC), ASHRAE Standard 90.1, and the International Green Construction Code (IgCC)—regarding the measurement of the surface radiative properties of roofing and exterior wall materials. The 2025 edition covers specimen preparation and test methods for measuring the initial and aged solar reflectance and thermal emittance of roofing and exterior wall materials. This marks the first time that an edition of the ANSI/CRRC S100 standard has included test methods and procedures for exterior wall materials, which will be helpful for compliance with the opaque wall reflectance and emittance provisions recently published in the 2024 IECC and IgCC.

Maintaining the ANSI/CRRC S100 standard plays a key role in the CRRC’s mission to bring objective, scientific information related to cool surfaces to critical discussions and informed decisions about the impacts of heat islands, extreme heat, and energy use in the built environment. “The ANSI/CRRC S100 is a cornerstone for the radiative property testing industry, providing standardized methods that ensure the accuracy and reliability of data critical for evaluating product performance and comparison of materials,” stated Michael Joyce, CRRC Consensus Body Chair and President of R&D Services. “This achievement is made possible by the dedicated efforts of our volunteer Consensus Body members, who represent a wide range of industry interests and worked tirelessly to keep the standard relevant and effective.”

The CRRC became an ANSI-Accredited Standards Developer Organization in 2008. After a three-year standards development process, the first edition of the standard was approved on November 16, 2010. The ANSI/CRRC S100 standard is now in its fifth edition and can be accessed for free on the CRRC website.