Windows Buying Guide

Aluminum: The Architect's Friend

Aluminum windows have been steadily losing market share to better, cheaper alternatives, such as fiberglass and vinyl. Nevertheless, aluminum windows have a number of distinct characteristics that make them attractive options.

Aluminum is extremely strong, meaning that windows can be fabricated with relatively thin frames and sash components. That provides more space in the window opening for glass and makes aluminum windows a favorite choice of architects. In addition, aluminum can be fabricated with an enormous variety of factory-applied color finishes that are extremely tough and long-lasting.

But in the competitive world of windows, aluminum's drawbacks stand out. Metal is a poor thermal performer, and it doesn't insulate well against heat and cold. The material expands and contracts rapidly relative to glass, putting stress on seals. And although it is impervious to moisture, insects and rot, aluminum is susceptible to the corrosive effects of salt air, so it's not a great choice for coastal climates.

A version of the all-aluminum window is the aluminum-clad variety, which features a wood core wrapped in an aluminum skin. Although these offer better insulating capabilities, they are outperformed by vinyl and fiberglass.