BS 644-2:1958

Types, sizes, construction of weight balanced and spring balanced windows, with and without glazing bars. Weight balanced windows from 1 ft 6 in to 6 ft wide and from 3 ft 9⅛ in to 5 ft 9⅛ in high, the spring balanced type being slightly smaller. Tables show sizes of masonry openings, glass sizes, number of panes, and daylight area.