How do I know which windows are energy efficient?You can check the energy efficiency of a window by looking at the BFRC, Certass or BSI label, also known as a “rainbow label”. The higher the energy rating, the more energy-efficient it is.By BPGS|2019-12-06T13:07:12+00:00December 6th, 2019|Share This Post With Others!FacebookTwitterLinkedInWhatsAppPinterestEmail