Granada Secondary Glazing is the UK’s largest manufacturer and supplier of secondary window glazing& installation, producing around 25,000 frames every year. We produce around 25,000 secondary glazing frames every single year, making us the largest secondary glazing manufacturer in the UK! Our range of secondary glazing is made to measure and built to last. We have a wide variety of products to choose from, whether you require vertical sliding secondary glazing for sash windows, or bespoke secondary glazing for custom window shapes, our team can design, manufacture and install the perfect solution for your home.