Wooden window frames:

Wood has been the long-established material for window frames. Because of its beauty, and its traditional design, wood many residential contractors and homeowners. From an energy efficient viewpoint, wooden framed windows do not conduct heat. A major draw back for wooden-frames is that wood is not essentially the most durable material. It is vulnerable to rot, however, if maintained wooded window frames may last an extremely long time. Painting the exterior surface not only permits you to protect your investment but also allows you to change the color schemes of your home.

Wood Clad:
To prevent rotting, some manufactures have clad or coated the exterior face of the window frames with either vinyl or aluminum. This cladding creates a permanent weatherproof exterior surface. The benefits of clad frames are that they provide low maintenance for the homeowner, at the same time keep the attractive wood finish many desire for the interior frames. Though the low maintenance of the vinyl and enamel metal claddings are often appreciated, the fact that they come in a limited
number of colors, limits the exterior color schemes.