Energy Efficiency & Ratings

Our window has been subjected to Window Energy Rating (WER) simulation calculations by an approved British Fenestration Ratings Council (BFRC) simulator.


The window has achieved an A-Rating which is supplied as standard.

Independently tested at a UKAS test house, our window has been evaluated in accordance with BS.6375 Part 1 “Performance of Windows: Classification for Weathertightness” against the test assessment methods laid down in BS.5368 and has achieved outstanding results. The figures achieved indicate that the tested Weather Performance Rating for our vertical sliding sash window will meet severe weather conditions.

BS.5368 Part 1 Permeability | 600Pa / Class 2

BS.5368 Part 2 Watertightness | 200Pa / Class 5A

BS.5368 Part 3 Wind Resistance | 1600Pa / Class 4