National Fenestration Ratings Council

When you are making a decision on replacement windows and/or sliding doors, you will probably want to compare the characteristics of different styles and brands. Being able to compare products objectively based on their performance will allow you to make better decisions and ultimately be happier with your purchase.

For this very reason, new replacement windows and sliding doors should have a label from the National Fenestration Rating Council (NFRC). The NFRC is a non-profit organization that administers the only uniform, independent rating and labeling system for the energy performance of windows, doors, and skylights, and the label outlines the characteristics of each product. In order to use this information wisely and choose the best product for your situation, it is necessary to understand the information that is included on each NFRC label.

The top line of the NFRC label includes the NFRC’s logo to prove authenticity, and on the right hand side is the name of the manufacturer and a description of the replacement window or patio door, including sliding door and hinged door styles.

The next line of information covers the energy performance ratings. This is the most important information if you are interested in taking advantage of the Federal tax credit for replacement windows. This section of the label includes U-Factor and Solar Heat Gain Coefficient (SHGC) ratings. In order to qualify for the tax credit, both figures must be equal to or less than 0.30.

The first figure, the U-Factor, rates the insulating properties of the replacement window. A lower number is ideal as this means that less heat is able to escape through the window. The second figure is the Solar Heat Gain Coefficient (SHGC), and it reveals how well the window blocks heat caused by the sun. This rating provides a number between 0 and 1; the lower the number, the less heat can be transmitted through the replacement window or sliding door.

The other figures on the NFRC label cover the additional performance ratings, such as Visible Transmittance, which is an indication of how much light comes through the window; the higher the number (between 0 and 1), the more light shines through.

You should now be able to read and fully understand the NFRC label for your prospective replacement windows and sliding doors. The first two figures are the most important for qualifying for the tax credit, but they are all important in the decision to find the right windows for you.