
An Intro to Insulated Glass First, a little background: modern windows are made as an assembly like a sandwich with with double (or sometimes triple) layers of glass with spacing between them, usually filled with Argon gas, which has 50% less heat conduction than air. This assembly is called insulated glass (IG) and generally a window or door sash will be made with one unit of insulated glass. To achieve a colonial or other decorative look, grills (in the old days called muntins) are added over the glass for a historic look in lots of configurations. Continue Reading →