What is double glazing?

Double glazing describes a high-performance window configuration constructed using an Insulated Glass Unit (IGU) featuring two parallel panes of glass separated by a continuous perimeter spacer bar and hermetically sealed together as a single component. The hollow internal cavity created between the two glass panes is completely dry and is typically filled with a dense, non-toxic insulating gas such as argon or krypton, which transfers heat far slower than standard air. This specialized design provides exceptional thermal insulation compared to obsolete single-pane windows. By restricting the flow of heat, double glazing keeps building interiors significantly warmer during cold winter months and cooler during hot summer months, drastically lowering energy bills. Furthermore, the dual-pane configuration acts as an effective sound barrier, noticeably reducing external noise transmission from traffic and city environments.