A bay window design is created when three or more windows are pushed outward from the main wall of a space to create a bay. A bay window adds a touch of elegance to a space. These windows can be used to create semi-octagonal, square, polygonal, and semi-hexagonal bays. Because of their combination of aesthetic appeal and usefulness, bay windows are regarded as one of the most sophisticated window types in interior architecture. There are many different bay window styles that today's designers have created, and each has a unique beauty.

Unplasticized polyvinyl chloride, or uPVC, bay windows are one type that has been very popular recently. These windows are the newest style available, and Fenesta, one of the top manufacturers of uPVC bay windows, offers a large selection of uPVC bay window styles. The many benefits these windows provide help to justify the price of the uPVC bay windows.