Window energy ratings (Energy Efficient Glass)

Part L of the Building Regulations for England and Wales (and Part F in Northern Ireland) includes Window Energy Ratings (WERs) as an alternative method of compliance.

The minimum level for replacement domestic windows is band E. For windows in new domestic extensions, the minimum requirement is band D. Additionally, in new dwellings, BFRC Ratings are now being used to guide building professionals towards more energy efficient design and building components.