Terms of the Trade: What Is Double Glazing?

A profile of two double glazed windows.

Double glazing or double glazed windows are made with two panes of glass in a single frame with space between them. The sealed air gap between the two panes of glass offers energy efficiency in the form of insulation, keeping heat inside the home during the winter and outside in the summer. Additional benefits include noise reduction and safety, since two panes of glass are harder to break than one.