Abstract: In a preferred embodiment, a method of replacing an existing window of the type having an existing fixed metal frame mounted in an existing window opening, the method including: removing elements of the existing window, except the existing fixed metal frame, while leaving the existing fixed metal frame in place and without rebuilding the existing window opening; providing a replacement window having a glazed monolithic frame member; and attaching the monolithic frame member to the existing metal frame by inserting fasteners through the monolithic frame member directly into the existing fixed metal frame.