Vinyl windows are generally less expensive than fiberglass windows; they are relatively energy efficient and come in many colors, but tend to expand in time, which can lead to leaks and cracks. Vinyl is one of the oldest forms of materials for residential windows; its use dates back to the 1970s, say authors at This Old House, when people needed windows in special sizes. The pliability of vinyl makes it easy to manipulate and size, and the low cost makes it appealing to many homeowners.
Vinyl windows have several appealing aspects. They give homeowners a low-cost, low-maintenance option for windows, although they do not come in as many colors as some other materials, like wood. Vinyl windows operate using a chamber system, which retains hot and cold air. This makes them relatively energy efficient, which can save money. Vinyl does not wear in time, unlike wood, and requires minimal maintenance besides the occasional touch-up coat of paint.
Fiberglass, in contrast to vinyl, is one of the newest arrivals on the window scene. Fiberglass is very durable and more energy efficient than vinyl. It is a natural insulator, and expands at a lower rate than vinyl, which reduces air leaks and cuts heating costs. Fiberglass windows resist shrinking, warping and cracking, which plague many other types of windows. They are, however, relatively expensive, and come in limited colors.