Aluminum Replacement Windows
Aluminum replacement windows were introduced into the marketplace prior to vinyl replacement windows. They were really the first material that replacement windows were made of. Though ideal for customized replacement window design, aluminum replacement window frames cause conductive heat loss (i.e., they have low R-values) and produce some amounts of condensation around the window frames. However, thermal breaks made of insulating plastic strips placed between the inside and outside of the frame and sash greatly improve the thermal resistance of aluminum replacement window frames.
Aluminum windows can be painted, unlike their vinyl window counterparts. However, the paint job will not be as good as one from a window frame made from wood.