Building Regulations and Window Energy Ratings
UK Building Regulations
UK Building Regulations dictate that all new and replacement windows must meet minimum requirements for thermal efficiency. The current requirement is that windows attain a whole window U-value of 1.4 Wm²K or better, or a Window Energy Rating (WER) of 'B' or 'A'.
Thermobar is a Passive House certified component - click here.
Building Regulations and WERs Page 1