Double glazing
Window composed of two panes separated by an insulating air or gas layer.
Full definition
Double glazing is an essential element of a building's thermal insulation, composed of two glass panes separated by a space filled with air or argon gas. In Belgium, single glazing is still present in about 15% of dwellings, mainly pre-war houses. Replacement with high-performance double glazing (coefficient Ug of 1.0 W/m2K or less) or triple glazing (Ug of 0.6 W/m2K or less) is eligible for regional grants. Replacement costs range from EUR 200 to 500/m2 depending on frame type (PVC, aluminum, wood). Grants amount to EUR 15-40/m2 in Wallonia and comparable amounts in Brussels and Flanders. Glazing replacement improves acoustic comfort, reduces condensation, and increases property value.