Insulated Glass Unit
A window assembly consisting of two or more panes of glass separated by a spacer bar and sealed to create an insulating air or gas-filled cavity.
An insulated glass unit (IGU), also called a sealed unit or double-glazed unit, is the core component of modern energy-efficient windows. The space between the glass panes is typically filled with argon or krypton gas to reduce heat transfer.
IGUs in Canada must meet CSA A440/NAFS performance standards. Common configurations include double-pane (two lites) and triple-pane (three lites). The spacer bar material significantly affects thermal performance — warm-edge spacers reduce condensation and heat loss at the glass edge.