Universal UPVC Windows and Doors is a leading manufacturer and Supplier of high-quality UPVC combination windows.One of the most distinctive types of windows you may use in your room are combination windows. Combination windows combine fixed, casement, and sliding windows in a way that best suits your needs and available space. Combination windows have the benefit of allowing you to combine your preferred types into a single, sturdy, and elegant frame. They offer great thermal insulation in addition to design versatility.