The revolutionary new Double and triple glazing Replacement Windows by Glass Tec has been designed with serenity, quality and calm in mind. Our Replacement Windows will blend seamlessly in to the fabric of your home combining outstanding energy efficiency performance with long life. They say that the only way to understand something is to find out what makes it tick, take it apart and analyse every component. Many existing PVC-U windows were literally broken down and evaluated, with every function analysed and improved. This is why we can confidently tell you that our double glazing windows and triple glazing replacement windows incorporate 25 improvements to make it one of the most advanced UPVC replacement Windows system in the market.