Lightwell

In architecture a lightwell, light well or air shaft is an unroofed external space provided within the volume of a large building to allow light and air to reach what would otherwise be a dark or unventilated area. Lightwells may be lined with glazed bricks to increase the reflection of sunlight within the space.

Lightwells serve to reduce the necessity for electric lighting, add a central space within the building, and provide an internal open space for windows to give an illusion of having a view outside.

A subterranean lightwell at the front of a building to provide light to a basement is called an area (or areaway in North American usage).

Use of the light well was known in ancient civilizations, including Egypt and at the Palace of Knossos on Minoan Crete. There are also instances of light well use by the Romans.

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