Building Regulations specifies that replacement windows for existing dwellings must achieve a minimum windows energy rating (WER) of band C for a whole window U value of 1.6 W/m²K is required.
We meet this target by suppling a 24mm double glazed units. This is made up of two layers of 4mm glass with the inner pane having a low "E" coating and a 16mm argon filled cavity. A warm edge spacer bars seperates to two panes of glass. This system will typical give a U value of 1.2 W/m²K