{{Short description|Air shaft or atrium}} thumb|Lightwell{{CSS image crop |Image = Aerial Closeup of the Pentagon, May 11, 2021.jpg |bSize = 700 |cWidth = 300 |cHeight = 300 |oTop = 150 |oLeft = 0 |Align=right|Description=Lightwells in the Pentagon}}
In architecture, a '''lightwell''',<ref group="NB">light well, light-well</ref> '''sky-well''',<ref group="NB">skywell, sky well</ref> or '''air shaft''' is an unroofed or roofed 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 may have sunlight reflecting mirrors on the top of light well.<ref>[https://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.506.3983&rep=rep1&type=pdf] Environmental assessment of light well in high-rise apartment building | Hisashi Kotania; ∗, Masaya Narasakia, Ryuji Satob, Toshio Yamanakaa | Department of Architectural Engineering, Graduate School of Engineering, Osaka University, Suita Osaka 565-0871, Japan | Department of Architecture, Osaka Institute of Technology, Osaka, Japan | 17 January 2002| Building and Environment 38 (2003) 283 – 289 | Size of light well (m) 13m × 12m × 62m (height)</ref>
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.
==Area or areaway== {{main|Area (architecture)}} A subterranean lightwell by any frontage of a building for light to a basement is also called an '''area''' (or '''areaway''' in North American usage). This may also allow pedestrian access to the building separate from a main door.
==Ancient history== The lightwell was used in ancient civilizations, such as the Egyptians<ref>{{cite book |title= The demography of Roman Egypt|last= Bagnall|first= Roger S|author2=Frier, Bruce W |date= 2006|publisher= Cambridge University Press|location= Cambridge, New York|isbn= 978-0-521-46123-8|oclc= 28927049}}</ref> and at the Palace of Knossos on Minoan Crete.<ref>{{cite web |url= http://www.themodernantiquarian.com/site/10854/knossos.html#fieldnotes|title= Knossos|access-date=2008-05-24 |last= Hogan|first= C Michael|date= 2008-04-14|work= The Modern Antiquarian}}</ref> There are also instances of lightwell use by the Romans, such as the impluvium and compluvium shaft.<ref>{{cite book |title= Piscinae: Artificial Fishponds in Roman Italy|last= Higginbotham|first= James Arnold|date= 1997|publisher= University of North Carolina Press|location= Chapel Hill, NC|isbn= 978-0-8078-2329-3|oclc= 35172558}}</ref> In traditional Chinese architecture, the 天井 (sky well) also exists.<ref>{{cite web |last1=You |first1=Xiaoying |title=How ancient 'skywells' are keeping Chinese homes cool |url=https://www.bbc.com/future/article/20230712-how-ancient-skywells-are-keeping-chinese-homes-cool |website=Future Planet |publisher=BBC |access-date=14 July 2023 |date=12 July 2023}}</ref>
==See also== {{Commons category|Lightwells}} *Atrium *Clerestory *Skylight *Light tube *Ventilation shaft *Daylighting
==Notes== {{reflist|group=NB}}
==References== {{reflist}}
{{Environmental technology}}
Category:Lighting Category:Solar architecture Category:Windows
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