Derw Glass uses Pilkington and Saint-Gobain Glass for all our double glazed and triple glazed units and windows. This ensures we have the best quality possible for you and your home. Derw Glass strives to achieve the highest standard.

Window Energy Ratings and A-rated windows – Current activity in UK. The Window Energy Ratings system is already being used as a benchmark to fairly assess the thermal efficiency of windows. The system allows different configurations of windows to be compared on a like-for-like basis on the thermal efficiency. Derw glass uses argon gas in the cavities for increased (WER) energy ratings coupled with warm-edge technology.

The Double Glazed Units made by Derw Glass are suitable for use in wooden and plastic frames and in most cases they can be fitted in to metal frames. All products used in the manufacture of our windows comply with CMS standard, ensuring the end product is of the highest quality.