I have never bought and installed my own windows before. Using the Modern UPVC site was simple and the design tools very easy to use. The design tool provides detailed guidance and explanation as you are presented with options to tailor the windows and doors to your own requirements. It helps you ensure that the windows you design are compliant with modern building regs. During the installation process I needed help regarding the positioning of fittings and I was able to get some guidance from Modern UPVC. They even replaced two glazing units that were damaged in the installation process. I am delighted with the quality of the products and the price I paid. The attached picture shows 5 of the 7 windows I bought and I have today bought 7 more windows and a door from them. I am happy to recommend their products and services to anyone in need of new windows.