Thermal insulation glass consisting of three individual panes, two of which usually have a coating. To comply with the energy values required by the EnEV, triple-glazed thermal insulation glass is practically obligatory today. Windows in passive houses are triple-glazed to reduce transmission heat losses; they let the sun in and the winter cold out. Frames with particularly good insulation properties are also used.

If one also takes into account that the solar energy entering free of charge through the passive house window can also cancel out the heat losses in the core winter, there are net energy gains if the window is aligned appropriately and not too much shading. The window has gone from being a “cold hole” to a “heating system”.

Nowadays, triple glazing “pays off” with every window purchase simply through the energy savings achieved.