Condensation forms very differently depending on whether it is inside or outside the building, due to the thermal bridge effect around the cavity. Surface condensation on the internal face always starts in the corners, mainly due to the additional cooling caused by the thermal bridge.

The high performance Low-E glass, such as SGG PLANITHERM series, or "warm-edge" spacebars, made of insulating material, such as SGG SWISSPACER, can effectively reduce the risk of condensation at the corners.