As window technologies have developed in recent years, so has the complexity of window shopping. Selection now requires decisions about glazing type, frame and sash construction, edge seals, air tightness, special convenience features, and an assortment of different finishes. To help you sort through the many options, this article looks at what's available in window components. Glazings Glazing is the most obvious part of a window — and the one that has gone through the greatest changes in recent years. The biggest development was the introduction of low-emissivity (low-e) coatings about ten years ago. A low-e coating can reduce the heat loss through a double layer of insulated glass by 50 percent (from a U-value of .49 to .25 — see chart, page 00). There are three types of low-e
