A window frame is an important part of every window, since it holds the window sash in place and supports the window glass. The material from which a window frame is made plays a significant part in not only the appearance of the window but also in the window's overall energy efficiency.
Window frames can be made from several different materials; each material has pros and cons associated with its effectiveness in a window frame. The four most common materials are:
Natural wood windows are a classic choice in window frames; wood has a look of warmth that is difficult to mimic using other materials. Although wood is one of the best insulating materials, it also requires more maintenance than other window frame materials and is susceptible to rot, mildew, and insect pests. Wood also has a tendency to shrink and swell with variations in temperature and moisture in the atmosphere.
Vinyl window frames are popular with many homeowners for their affordability and ease of maintenance. Available in a range of styles, vinyl windows can look similar to wood and have an integral color which makes painting unnecessary. Vinyl is quite a good insulator and requires minimal upkeep over time; most vinyl windows need only a brief cleaning with a hose once each year.
Aluminum is an excellent choice as a window frame material for homeowners who are looking for something lightweight yet durable. While in the past aluminum frames have provided relatively poor insulation, modern aluminum replacement windows are often constructed with a thermal break made from a material with better energy efficiency. Aluminum is strong and requires very little maintenance, and it can be painted in any color to match the exterior decor of the home.
Fiberglass window frames are one of the newer options in the window frame market; fiberglass is more expensive than vinyl or aluminum as a window material, but it offers excellent insulating properties and is both low-maintenance and lightweight. Fiberglass expands and contracts at the same rate as the glass within the window panes, which helps to ensure the integrity of the glass seals. Like wood and aluminum, fiberglass frames can be painted in any color.