How to Read (Those Darn) Window Performance Stickers

Posted May 30, 2011 6:28 AM by Tristan Roberts at BuildingGreen.com

Before you peel that NFRC sticker off the window, check the numbers and ask whether you got the right window for your climate.

Have you ever found yourself picking a sticker off a building product or material from the store, and wondering, why did they put the sticker here? I have often had this thought with everything from stovepipe to plumbing fittings, but the classic example in the building world is probably windows.

The glass part of the window is for looking through, right? Then why does every window manufacturer put two are three large stickers right in that area? Sometimes these come off easily--sometimes they are a real pain to remove. Sometimes they don't come off at all: I have seen window stickers, or remnants of them, still in place years after construction.

The next time you encounter one of those stickers--in your house, on the construction site, or at the showroom, take a close look. The different values that appear on them can mean a world of difference in terms of how those windows will perform in your building.

Read More about NFRC, U-factor, SHGC and what it all means for the building envelope.