NFRC Rating

What Is the NFRC?

The National Fenestration Rating Council (NFRC) is an independent organization that develops and administers energy performance ratings for windows, doors, and skylights. NFRC-certified products carry a label that allows consumers to compare performance across brands and models.

Key Ratings on the Label

• U-Factor: Measures heat loss. Lower is better.
• Solar Heat Gain Coefficient (SHGC): Measures solar heat entering. Lower is better for cooling-dominated climates.
• Visible Transmittance (VT): Amount of visible light that passes through. Higher means more natural light.
• Air Leakage (AL): Rate of air infiltration. Lower is better.

Why It Matters

NFRC ratings are based on standardized testing, so you can reliably compare windows from different manufacturers. ENERGY STAR certification uses NFRC ratings to determine which products qualify for each climate zone.

For Bay Area Homeowners

When choosing replacement windows in the Bay Area, look for the NFRC label to understand U-factor and SHGC. These values help ensure your windows meet local energy goals and perform well in our mild, cooling-dominated climate.