The term warm edge describes the glazing edge of a mutli-pane insulating glass unit, in which the spacer bar between the panes of glass is made from a material with low thermal conductivity. That helps to reduce the thermal bridge from inside to outside – thus saving energy and avoiding the formation of mould on the glass edge

Heat loss especially from windows is a common source of inefficiency in a structure's thermal insulation. The sealed unit edge, where the spacer bar connects the two glass panels, can be a weak point for thermal bridging. This can cause undesired heat transfer, leading to possible condensation on windows that can impair visibility and comfort. To address this issue, Northern Express Glass has incorporated an advanced warm-edge spacer system. It is created with a top-of-the-line composite plastic that can significantly reduce the thermal bridge and, consequently, minimise the risk of condensation and cold spots. This technology enhances our products' overall performance and ensures a more comfortable and energy-efficient home or building. This bar differs little in appearance from conventional spacer bars and complies with EN1279 Parts 2 and 3.