Skylight

A skylight is a light-transmitting structure that forms all or part of the roof space of a building for daylighting purposes.A large (20' x 20') steel and glass retractable skylight, seen from the roof. Note the steel tracks that the skylight rolls on, to retract.The same retractable skylight, seen from the interior. This is a bi-parting skylight, meaning that it parts in the middle to open.This ridge skylight wraps over the highest point of the roof - the ridgeline.This is that same skylight, from the inside. Steel allows large spans, without a grid of supporting tubes and cables.TDD skylight on the roof terrace of Liverpool Central LibraryActive daylighting uses a tubular daylight device—TDD A skylight is a light-transmitting structure that forms all or part of the roof space of a building for daylighting purposes. Open skylights were used in Ancient Roman architecture, such as the oculus of the Pantheon. Glazed 'closed' skylights have been in use since the Industrial Revolution made advances in glass production manufacturing. Mass production units since the mid-20th century have brought skylights to many uses and contexts. Energy conservation has brought new motivation, design innovation, transmission options, and efficiency rating systems for skylights. Prior to the Industrial Revolution, it was France that probably had the leading technology in architectural glass. One of the earliest forms of the glass skylight can be seen at the Palace of Versailles in the Galerie des Batailles, which was added onto the existing palace by Louis Philippe in the year 1830. Another form that displays early sky lighting technology is the Halle aux blés (Paris) built in 1763-67. This form of natural overhead lighting allowed for illumination while decoration could cover the entire interior wall, and it is the option least obstructed by other buildings. This means that sky lighting as we know it, in many forms today, was probably pioneered in France during the early 18th century or late 17th century. According to architectural glass, the earliest functional skylights would have been formed by either glass casting, crown glass (window), cylinder blown sheet, and machine drawn cylinder sheet, or fourcault process. Skylighting types include roof windows, unit skylights, tubular daylighting devices (TDDs), sloped glazing, and custom skylights. Uses include: