The energy classification of windows
The energy classification of windows aims the facilitate the comparisons between different window solutions made by builders and renovators. The energy classification of windows is voluntary for manufacturers.
In the energy classification, the window is calculated a comparative figure, which indicates how much heating need the window structure generates in a year. Windows are given an energy label familiar from household appliances; in the energy label for windows, the windows are divided into classes on a scale of A++–G.