Sound Proof Windows

Secondary glazing is an additional internal window system installed on the room side of an existing window to improve insulation, reduce noise, and enhance security without replacing the primary frame. Instead of removing the original window, a slim, separate pane of glass—set within its own discreet frame—is fitted to the inside reveal, creating a sealed air gap between the two layers.

This design forms a double-glazing effect that cuts heat loss, limits drafts, and helps maintain a stable indoor temperature. The air cavity acts as a thermal buffer, reducing energy consumption and condensation on the interior pane. When specified with laminated or acoustic glass and a deep air gap, secondary glazing can also deliver excellent soundproofing, often outperforming standard double-glazed units for properties near busy roads, rail lines, or airports.