Back in the early 1980s, window, door and skylight manufacturers introduced new technologies designed to improve the energy performance of their products. Unfortunately, consumers had no good way to judge the effectiveness of these technologies, or to compare the performance of different products accurately and reliably. With the federal government beginning to think about establishing an independent agency to rate fenestration energy performance, the industry decided to take the initiative and formed NFRC in 1989.

Today fenestration manufacturers can rate the U-Factor, solar heat gain coefficient (SHGC), visible transmittance (VT), air leakage (AL), and condensation resistance (CR) of their products through the NFRC system. The Council has also developed rating and labeling procedures for window film attachments, internal or between the glass blinds and shading devices, and dynamic glazing products that change tint in response to temperature, sunlight, or electric charge. NFRC is currently considering such energy ratings as ultraviolet light/fade protection, and overall comfort.