High Performance Windows for Structural and Energy Performance

The Department of Energy (DOE) now makes it easier to find windows with beyond-code insulating performance and commercial-grade structural strength. Since 2010, the DOE High Performance Windows Volume Purchase Program has promoted residential windows with a U-factor of 0.22 or less through a web portal including product and vendor information. Since the start of the program’s second phase in May 2011, it includes windows with CW and AW performance classes, according to the North American Fenestration Standard.

The program allows a somewhat higher U-factor for windows with these performance classes: The U-factor limit is 0.27 for operable CW class windows and 0.32 for operable AW class windows. These adjusted criteria reflect that the incremental cost of reducing the U-factor of windows with high structural performance can be steep. At any rate, these U-factor criteria substantially exceed code requirements for windows in commercial and high-rise residential buildings.

For more information on the DOE Windows Volume Purchase Program and on the applicable specifications, view www.windowsvolumepurchase.org.

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This article was adapted from the Summer 2011 Word on Windows, which is the Efficient Windows Collaborative's newsletter. The Efficient Windows Collaborative is the Alliance’s consortium dedicated to increasing the market share of high-efficiency windows in both the residential and commercial sectors.