When you go for a window replacement exercise for your home, you have two very good choices. One is vinyl and the other is fiberglass. Vinyl windows are made from polyvinyl chloride or PVC which is the same PVC used to make plumbing pipes, electrical pipes and many other plastic items. Polyvinyl chloride is a combination of different chemicals, plasticizers and pigments. For these reasons environmental concerns have been raised against vinyl but much of that has been resolved now. Fiberglass windows are made from glass fibers that are combined together to make sheets.
While choosing between the two it is not of much use looking at the websites of manufacturers as each manufacturer will claim that there windows are the best. Thus the fiberglass window manufacturers will propagate the advantages of fiberglass windows while vinyl manufacturers will do the same about vinyl windows.
It is difficult to choose between fiberglass and vinyl as each has its own strengths and weaknesses. It will depend a lot on what your needs are. What goes well with the interiors and exteriors of your home is also a matter. Budget needs to be kept in mind as well. Both the types come in a variety colors and designs.
Fiberglass windows offer much less insulation than vinyl windows. Vinyl windows are designed to trap pockets of air and thus are very efficient in keeping out cold. Fiberglass offers to up to 3 times less insulation than vinyl. So if you are looking for insulation your choice has to be vinyl windows.
However it is claimed that fiberglass windows has much more strength than vinyl windows. Though this can be debated the highest quality fiberglass windows generally outlast the vinyl windows. It is certainly true that fiberglass windows contract and expand less than vinyl windows because of temperature change. As a result they suffer less from weather changes. Vinyl windows are prone to warping, rotting, cracking, bowing and shrinking in areas with severe weathers. These problems are not faced if you use fiberglass windows as they are less brittle and less affected by temperature change.
Fiberglass windows can be repainted. However vinyl windows do not hold paint. But at the same time they do not ever need a repaint, the way they are made. On the other hand if you want to change the look of your house later on fiberglass windows give you the option of changing the colors of the windows without going in for new windows.