A rooflight is a window set into the plane of a roof, lying flat or at the same pitch as the roof covering, to admit daylight into attics, stairwells and other spaces below. It differs from a roof lantern, which stands up above the roof, and from a dormer, which projects vertically with its own small roof.
Traditional cast-iron rooflights, often small and hinged to open for ventilation, were produced in large numbers during the nineteenth century for farm buildings, workshops, mills, terraced houses and servants' attics. Their slim frames sit almost flush with slate or tile, so they disturb the roofline far less than later bulky timber or plastic units. For this reason planning and conservation officers frequently ask for slim conservation-style rooflights on listed buildings and in conservation areas, and several manufacturers now make steel replicas of the Victorian pattern with modern double glazing. Original cast-iron rooflights are sometimes found through architectural salvage, although they usually need repair, new glass and careful weatherproofing before reuse. Whatever type is chosen, their size, number and position should be considered carefully to respect the character of the roof.
