National Fenestration Rating Council

NFRC is the nation's largest independent, third-party rating and labeling system for the energy performance of fenestration products. As a 501(c)(3), a nonprofit organization that serves the public by establishing objective window, door, and skylight energy performance ratings that help consumers compare products and make informed purchase decisions. NFRC is a membership organization whose members include a variety of stakeholders, including architects, government and code officials, manufacturers, researchers, laboratories and other not-for-profit organizations.