National Fenestration Rating Council (NFRC)
National organization that sets standards for windows and doors.

NFRC is a non-profit organization that administers the only uniform, independent rating and labeling system for the energy performance of windows, doors, skylights, and attachment products. Our goal is to provide fair, accurate, and reliable energy performance ratings so that:

•  Architects, builders, code officials, contractors, homeowners, and others can compare different products and make informed product choices.

•  Building officials, state government employees, and others involved in code development and enforcement can determine if products meet local codes.

•  Government- and utility-run energy efficiency programs can establish performance requirements and standards.

•  Manufacturers have a fair and level playing field to compare products and an accurate method of showing the energy benefits of new designs or technology.