When you’re shopping for new windows and doing pre-purchase research, you’ll likely come across terms and organizations you haven’t heard of before and wonder how they should fit into your decisions about which replacement windows are right for your home. One example is the NFRC.

What is the NFRC?

The National Fenestration Rating Council (NFRC) is a non-profit organization that establishes energy performance ratings for windows, doors, and skylights. These ratings can then be used by consumers to help them make informed decisions when investing in new windows.

The NFRC doesn’t only establish ratings, they also help consumers understand the ratings. What the NFRC does NOT do is recommend or sell particular products, so consumers can count on us to provide non-bias ratings and advice.

Is This the Same as The ENERGY STAR Label?

The ENERGY STAR label lets you know whether or not an item is energy efficient, but the NFRC goes further by helping consumers compare windows and doors by providing ratings in several categories, so they provide a deeper dive into the performance of each product.

Breaking Down the NFRC Label

When you look at an NFRC label, you’ll see the name of the manufacturer and the model number of the door or window along with four numbers:


This range shows how well a product will stop heat from leaking out of a home through a window or door. The range is 0.20-1.20.

Solar Heat Gain Coefficient

This measurement shows how well a product prevents unwanted heat gain. The range is 0-1.

Visible Transmittance

This measurement shows how much light a window will allow to enter. The range is 0-1.

Air Leakage

This number shows how much air will enter through the door or window. The range is less than 0.3.

For ratings on U-Factor, Solar Heat Gain Coefficient, and Air Leakage, low numbers are better. For Visible Transmittance, a higher number is better.

Learn More from Our Experienced Chicagoland Window Specialists

Since 1996, WindowWorks has been the trusted choice for new windows in the Chicagoland area. Contact us today for more information and join the more than 50,000 customers enjoying the beauty and energy-efficient performance our windows provide. Call today or fill out our online form now to schedule a free consultation.