Both are important window terms you should understand if you’re looking at new windows for your home. New and replacement windows are evaluated by the independent organization the National Fenestration Rating Council® (NFRC). It’s their goal that homeowners can compare windows for energy efficiency and other factors easily.

U-Factor A.K.A. U-Value

Where a sales person or brochure refers to the window’s u-factor or u-value, it’s the same thing. This term refers to the heat transference of the window. Although the NFRC rates the entire window, some manufacturers will also give you a center of the glass u-factor. Be careful when comparing window’s u-factors that you are comparing total window ratings and not one center of the glass and one whole window. U-factor is expressed with a range of .2 to 1.20. Because this term refers to heat loss, it’s not the biggest consideration for Arlington homeowners. The recommended number for u-factor in Texas is below .35.


SHGC refers to the window’s Solar Heat Gain Coefficient. And, because of where we live, this is a very important factor to consider in your new or replacement windows. The SHGC rating refers to the window’s ability to block the sun’s radiant heat. This too is expressed in a decimal with a lower number being better. Dallas-Fort Worth and Arlington homeowners should look only at replacement windows with a SHGC of .25 or lower.

ENERGY STAR® Compliant

In fact, if you want an ENERGY STAR compliant window, you must select windows that meet the current recommendations of .35 and lower for u-value and .25 and lower for SHGC. You can find windows of all styles and frame materials that meet these values.

Affordable Replacement Window Systems offers several brands and many styles of ENERGY STAR compliant windows for homes throughout the greater DFW Metro area. If you’re looking for quality and affordable replacement windows, call or text us today at (817) 264-6509 or fill out our contact form to schedule your free quote.

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