enegy efficent window label new windows

Example of an NFRC Window Rating Sticker

Many of the families looking to replace their windows have never bought new windows before. That often means they’re unfamiliar with the terms so easily said and used by window companies. We want you to be completely confident in your window choice, which is why we are explaining these terms all in one place.


The NFRC is an independent non-profit organization that certifies the performance of both new construction and replacement windows. NFRC stands for National Fenestration Rating Council. Every window they evaluate has a label with key criteria to help you compare different windows, even those from different manufacturers, using the same scale. Basically, it allows you to compare the windows to one another in an apples to apples fashion.

ENERGY STAR® Rated Window

Often, you’ll see the Energy Star logo on the NFRC label indicating that the window meets or exceeds the energy efficiency guidelines for the locations the window is sold. The guidelines are established for different regions of the country by the U.S. Environmental Protection Agency (EPA) to help protect the climate and, as a result, save people money on heating and cooling.


U-factor is one of the elements of the window that the NFRC evaluates. This helps you evaluate how insulative the window is. The lower the number, on a 0 – 1 scale, the more energy efficient the window.

Solar Heat Gain Coefficient

This mouthful isnew often abbreviated as SHGC. Think about your current windows and how hot to the touch they can be or how warm it feels standing in front of one on a day where the sun shines on them. New windows reduce the amount of solar energy, or heat, that comes into your home through your windows. This too is measured on a 0 – 1 scale with the better window having a lower number on the scale.

Visible Transmittance

Although this term doesn’t have anything to do with the energy efficiency of the window, it speaks to the amount of visible light that the window lets in. Again, expressed on a 0 – 1 scale, where the higher number lets in more visible light than a lower number.

We understand that buying new windows can be confusing. As a window company with 65 years in Indianapolis, we want to help you feel comfortable with your decision. We’ll happily answer any questions you have before you buy, during the installation and after. If you’re looking for new windows from a local window company with experience, call Blair Windows & Doors. We offer windows from many different companies and stand behind the work we do 100%. Call (317) 356-4666 or fill out our contact form today.

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