Editing Bay window

{{Short description|Architectural element}}
{{More citations needed|date=January 2014}}
{{Use dmy dates|date=October 2023}}
[[File:Lengerich Bahnhofstrasse 18 Haus Jasper 02.jpg|thumb|right|A [[canted (architecture)|canted]] oriel window in [[Lengerich, Westphalia|Lengerich]], Germany]]

A '''bay window''' is a [[window]] space projecting outward from the main [[wall]]s of a building and forming a [[bay (architecture)|bay]] in a room.  A [[bow window]] is a form of bay with a curve rather than angular facets; an [[oriel window]] is a bay window that does not touch the ground.

A window may be all three: projecting outward from the main fascia of a wall, curved in shape, and not reaching the ground.  A bay window may be supported from the ground by a foundation, or in space by [[corbel]]s, [[bracket (architecture)|brackets]], or [[cantilever]].

A typical bay window consists of a central windowpane, called a fixed sash, flanked by two or more smaller windows, known as casement or double-hung windows. The arrangement creates a panoramic view of the outside, allows more natural light to enter the room, and provides additional space within the room. Bay windows are often designed to extend beyond the exterior wall, either adding to floor space, often filled with a table, desk, or seating area, or turned into a window seat (often with storage or a grated radiator below). They are found both in residential buildings, particularly in living rooms, studies, dining areas, or bedrooms, and in commercial and public structures.

==Types==
[[File:Bay Window (PSF).jpg|thumb|left|Typical residential [[canted (architecture)|canted]] bay window, supported by a foundation and rising from the ground]]

Bay window is a generic term for all protruding window constructions, regardless of whether they are curved like a [[bow window]] or angular, start from the ground, and run over one or multiple [[storey]]s.

In plan, the most frequently used shapes are [[isosceles trapezoid]] (which may be referred to as a ''[[canted (architecture)|canted]] bay window''<ref>[http://www.medievalarchitecture.net/documents/glossary.pdf ''Glossary of Architectural Terms''] {{webarchive |url=https://web.archive.org/web/20120914001323/http://www.medievalarchitecture.net/documents/glossary.pdf |date=14 September 2012 }} [[s.v.]] ''Bay Window''.</ref>) and [[rectangle]]. But other [[polygonal]] shapes with more than three faces are also common, as are curved shapes. If a bay window is curved it may alternatively be called ''[[bow window]].''<ref>[[John Fleming (art historian)|John Fleming]], [[Hugh Honour]], [[Nikolaus Pevsner]], The [[Penguin Books|Penguin]] Dictionary of Architecture, Fourth edition, [[Harmondsworth]] 1991, p. 36.</ref> The angles most commonly used on the inside corners of the bay are 90, 135 and 150 [[degree (angle)|degree]]s.  Bay windows in a [[triangular]] shape with just one corner exist, but are relatively rare.

A bay window that does not reach the ground and is supported by a [[corbel]], [[bracket (architecture)|bracket]], [[cantilever]], or similar is called an [[oriel window]].

==Uses==
Bay windows can make a room appear larger, and provide views of the outside which would be unavailable with an ordinary flat window. They are found in [[terraced house]]s, [[Semi-detached|semis]], and [[Single-family detached home|detached houses]] as well as in blocks of [[apartment|flats]].

In commercial structures bay windows allow an expanded footprint out into "public space", ideal for showroom windows; in multi-story commercial structures, particularly early skyscrapers, they increased a building's space without adding to its taxable footprint or expanding from the ground up into public space. 

Based on British models, their use spread to other English-speaking countries like Ireland, the US, Canada, and Australia. Following the pioneering model of pre-modern commercial architecture at the [[Oriel Chambers]] in [[Liverpool]], they feature on early [[Chicago school (architecture)|Chicago School]] skyscrapers, where they often run the whole height of the building's upper storeys.{{Citation needed|date=April 2018}} They also feature in [[bay-and-gable]] houses commonly found in older portions of [[Toronto]].

Particularly during the [[Gothic architecture|Gothic]] period bay windows often served as small house [[chapel]]s, containing an [[altar]] and resembling an [[apse]] of a church. Especially in [[Nuremberg]] these are even called {{lang|de|Chörlein}} ({{literally|little apse/[[Choir (architecture)|choir]]}}), with the most famous example being the one from the [[parsonage]] of [[St. Sebaldus Church]].

In [[medieval architecture|medieval]] times and up to the [[Baroque architecture|Baroque]] era most bay windows were oriels, and frequently appear as a highly [[Ornament (art)|ornamented]] addition to the building rather than an organic part of it. 

In [[Islamic architecture]], oriel windows such as the Arabic [[mashrabiya]] are frequently made of wood and in warm climates serve the general function of an enclosed [[balcony]], providing greater privacy and relief from the sun.

Bay windows were identified as a defining characteristic of [[San Francisco]] architecture in a 2012 study that had a [[machine learning]] algorithm examine a random sample of 25,000 photos of cities from [[Google Street View]].<ref>{{cite web |url=http://gigaom.com/cloud/big-data-magic-trick-show-me-a-doorway-ill-tell-you-the-city/ |title=Big data magic trick: Show me a doorway, I'll tell you the city |first=Derrick |last=Harris |date=10 August 2012 |publisher=[[GigaOM]] |access-date=21 October 2012}}</ref>

== Gallery ==
<gallery>
File:Nürnberg Sebalder Pfarrhof Sebalder Chörlein.jpg| {{lang|de|Chörlein}} at the [[parsonage]] of [[St. Sebaldus Church]], [[Nuremberg]], before 1361<ref>[http://objektkatalog.gnm.de/objekt/A3775 Inventary] of [[Germanisches Nationalmuseum]] where the original is kept while the image shows a 1902 replica</ref>
File:FR Colmar 20080828 026.jpg|Two superposed Renaissance oriel windows in [[Colmar]], France
File:Erker und Fassadenmalereien in Stein am Rhein.jpg|Market square in [[Stein am Rhein]], Switzerland
File:Exeter College Bay Window in Turl Street.jpg|An oriel window in [[Turl Street, Oxford|Turl Street]] belonging to [[Exeter College, Oxford]]
File:Back is best - geograph.org.uk - 1225942.jpg|Rear of the Clarence Mansions, a [[grade II* listed]]<ref>[http://www.britishlistedbuildings.co.uk/en-481585-numbers-1-6-clarence-mansions-numbers-1- British Listed Buildings]</ref> luxurious 19th-century [[Regency architecture|Regency]] apartment block in [[Leamington Spa]], Warwickshire, England
File:585 and 587 Broadway, Chadderton - geograph.org.uk - 1083455.jpg|Typical 1930s bay-fronted [[Semi-detached|semis]] in [[Chadderton]], [[Greater Manchester]]
File:Dudley Drive - geograph.org.uk - 580164.jpg|Flats in [[Hyndland]], [[Glasgow]], late 19th or early 20th century
File:Oriel chambers.jpg|[[Oriel Chambers]], [[Liverpool]], by [[Peter Ellis (architect)|Peter Ellis]], 1864
File:20110805Hellwigstr7-13 Saarbruecken5.jpg|Triangular oriel windows in Hellwigstrasse, [[Saarbrücken]], Germany, 1927
File:Carved balcony, Mehrangarh Fort.jpg|[[Mehrangarh Fort]], India
File:GD-EG-Caire-Suhaymi044.JPG|[[Mashrabiya]], [[Bayt Al-Suhaymi]], [[Cairo]], Egypt
File:Kairo Gayer Anderson Museum BW 9.jpg|[[Gayer-Anderson Museum]], Cairo, Egypt
File:2014 Kłodzko, pl. Chrobrego 13 03.JPG|[[Kłodzko]], Poland
File:Bruges - Bay window.JPG|[[Bruges]], Belgium
File:Naseef House 1.jpg|Traditional "rawashin" bay windows on [[Nasseef House]] in [[Jeddah]], Saudi Arabia<ref>{{cite news| url=https://www.arabnews.com/rawashin-distinctive-style-heritage-buildings-jeddah | title=Rawashin, the distinctive style of heritage buildings in Jeddah | work=[[Arab News]] | date=10 November 2012 | accessdate=27 July 2021 }}</ref>
File:Bay window (PSF).png|Typical interior of a full-height single-story residential bay window 
File:MultiStoryBayWindow.jpg|Interior of a multi-story bay window in [[Chicago]], [[Illinois]]
File:Box window section drawing.jpg|Bay window section drawing
</gallery>

==See also==
* [[Caboose#Bay window|Caboose bay window]]
* [[Bow window]]
* [[Bretèche]]
* [[Oriel window]]

==References==
{{Reflist}}

==External links==
{{Commons category|Bay windows}}
* {{cite news |title=Gaining bonus space and light with bay windows |first=Jerome |last=Gagnon |url=http://www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2004/11/24/HOG6U9V2641.DTL |newspaper=[[San Francisco Chronicle]] |date=24 November 2004 |access-date=21 October 2012}}

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[[Category:Architectural elements]]
[[Category:Architecture in the San Francisco Bay Area]]
[[Category:Windows]]