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Gable dormers at Hospices de Beaune in Beaune, France Beaune (21) Hotel-Dieu - Cour - 02.jpg
Gable dormers at Hospices de Beaune in Beaune, France
Pair of hip roof dormer windows on the Howard Memorial Hall, Letchworth Paired dormer windows, Letchworth (geograph 4237604).jpg
Pair of hip roof dormer windows on the Howard Memorial Hall, Letchworth

A dormer is a roofed structure, often containing a window, that projects vertically beyond the plane of a pitched roof. [1] A dormer window (also called dormer) is a form of roof window.


Dormers are commonly used to increase the usable space in a loft and to create window openings in a roof plane. [2] A dormer is often one of the primary elements of a loft conversion. As a prominent element of many buildings, different types of dormer have evolved to complement different styles of architecture. When the structure appears on the spires of churches and cathedrals, it is usually referred to as a lucarne.


The word dormer is derived from the Middle French dormeor, meaning "sleeping room", [3] as dormer windows often provided light and space to attic-level bedrooms. [2]

One of the earliest uses of dormers was in the form of lucarnes, slender dormers which provided ventilation to the spires of English Gothic churches and cathedrals. An early example are the lucarnes of the spire of Christ Church Cathedral, Oxford. Dormer windows have been used in domestic architecture in Britain since the 16th century. [4]

Dormer windows were popularised by French architect François Mansart, who used dormers extensively in the mansard roofs he designed for 17th-century Paris. [5]

Today dormers are a widespread feature of pitched roof buildings.


Some of the different types of dormer are:

Requirements for permission to construct

In some localities, permission must be sought for construction of dormers and other features. In England and Wales, the General Permitted Development Order states classes of development for which such planning permission is not required. [13] Such rights are only applicable outside conservation areas, national parks, Areas of Outstanding Natural Beauty or The Broads. [13] Dormers may introduce imbalance in the street scene and be seen as inappropriate within the local setting of streets and buildings. [14]


Dormers are popular in Ulster, [15] and commonly used to create extra space when a loft is converted into a habitable room. [16]

See also

Related Research Articles

Roof top covering of a building

A roof is the top covering of a building, including all materials and constructions necessary to support it on the walls of the building or on uprights; it provides protection against rain, snow, sunlight, extremes of temperature, and wind. A roof is part of the building envelope.

Bungalow Type of building, originally developed in the Bengal region in South Asia, but now found throughout the world

A bungalow is a small house or cottage that is either single-storey or has a second storey built into a sloping roof, and may be surrounded by wide verandas.

Mansard roof four-sided gambrel-style hip roof

A mansard or mansard roof is a four-sided gambrel-style hip roof characterized by two slopes on each of its sides with the lower slope, punctured by dormer windows, at a steeper angle than the upper. The steep roof with windows creates an additional floor of habitable space, and reduces the overall height of the roof for a given number of habitable stories. The upper slope of the roof may not be visible from street level when viewed from close proximity to the building.

Gable Architectural feature

A gable is the generally triangular portion of a wall between the edges of intersecting roof pitches. The shape of the gable and how it is detailed depends on the structural system used, which reflects climate, material availability, and aesthetic concerns. A gable wall or gable end more commonly refers to the entire wall, including the gable and the wall below it. Some types of roofs do not have a gable. One common type of roof with gables, the gable roof, is named after its prominent gables.

Tented roof type of polygonal hipped roof with steeply pitched slopes rising to a peak

A tented roof is a type of polygonal hipped roof with steeply pitched slopes rising to a peak. Tented roofs, a hallmark of medieval religious architecture, were widely used to cover churches with steep, conical roof structures.


In architecture, a lucarne is a feature of a warehouse, mill or factory. A window or opening high up on an outside wall supports a hoist above doors on the floors below.

This page is a glossary of architecture.

Mono-pitched roof roof consisting of a single sloping surface

A mono-pitched roof, often referred to as a pent roof, shed roof, lean-to roof, and/or skillion roof, is a single-sloped roof surface, often not attached to another roof surface. This is in contrast to a dual-pitched roof, also known as a gabled roof, which is pitched in two different directions.

Loft conversion

A loft conversion or an attic conversion is the process of transforming an empty attic space or loft into a functional room, typically used as a bedroom, office space, a gym, or storage space. Loft conversions are one of the most popular forms of home improvement in the United Kingdom as a result of their numerous perceived benefits. The installation of a loft conversion is a complicated process, and whilst it may be possible to attempt a 'DIY' loft conversion, the large amount of work involved often results in many people choosing to contract a specialist loft conversion company to undertake the task.

Normandy Grange United States historic place

Normandy Grange is located along NY 9D north of Garrison, New York, United States. It is a Norman-style house and farm complex built in the early 20th century.

House at 356 Albany Avenue United States historic place

The house at 356 Albany Avenue in Kingston, New York, United States is a frame house built near the end of the 19th century. It is in the Queen Anne architectural style.

H. R. Stevens House United States historic place

The H.R. Stevens House is located on Congers Road in the New City section of the Town of Clarkstown, New York, United States. It is a stone house dating to the late 18th century. In the early 19th century it was expanded with some wood frame upper stories added later. The interior was also renovated over the course of the century.

North Grove Street Historic District United States historic place

The North Grove Street Historic District is located along the north end of that street in Tarrytown, New York, United States. It consists of five mid-19th century residences, on both sides of the street, and a carriage barn. In 1979 it was listed on the National Register of Historic Places.

Central-passage house

The central-passage house, also known variously as center-hall house, hall-passage-parlor house, Williamsburg cottage, and Tidewater-type cottage, was a vernacular, or folk form, house type from the colonial period onward into the 19th century in the United States.

Jackson Park Town Site Addition Brick Row United States historic place

Jackson Park Town Site Addition Brick Row is a group of three historic houses and two frame garages located on the west side of the 300 block of South Third Street in Lander, Wyoming. Two of the homes were built in 1917, and the third in 1919. The properties were added to the National Register of Historic Places on February 27, 2003.

Hip roof Type of roof where all sides slope downwards to the walls

A hip roof, hip-roof or hipped roof, is a type of roof where all sides slope downwards to the walls, usually with a fairly gentle slope. Thus, a hipped roof house has no gables or other vertical sides to the roof.

Nappanee Eastside Historic District United States historic place

Nappanee Eastside Historic District is a national historic district located at Nappanee, Elkhart County, Indiana. The district encompasses 138 contributing buildings in a predominantly residential section of Nappanee. It was developed between about 1880 and 1940, and includes notable examples of Italianate, Queen Anne, Colonial Revival, and Prairie School style architecture. Located in the district are the separately listed Frank and Katharine Coppes House and Arthur Miller House.

The San Juan Historic District in San Juan, New Mexico is a 23 acres (9.3 ha) historic district which was listed on the National Register of Historic Places in 1988. The listing included 14 contributing buildings and two non-contributing buildings.


  1. "Definition of dormer". Archived from the original on 9 August 2016. Retrieved 23 May 2016.
  2. 1 2 Barr, Peter. "Illustrated Glossary - 19th Century Adrian Architecture". Retrieved May 23, 2016.
  3. "Etymology of "dormer"". Online Etymology Dictionary. Retrieved 23 May 2016.
  4. "Traditional Dormer Windows: Design Guide". Tewkesbury Borough Council. Retrieved 23 May 2016.
  5. Maddox, Nathania. "ABOUT DORMERS". Archived from the original on December 8, 2015. Retrieved June 17, 2015.
  6. "Dormer Types: Gabled". Retrieved 25 May 2016.
  7. "Dormer Types: Hipped". Retrieved 25 May 2016.
  8. Dictionary of Architecture & Construction, C.M.Harris.
  9. "Eyebrow". Retrieved 2012-09-28.
  10. A Visual Dictionary of Architecture. Francis D.K. Ching
  11. Gitlin, Jane (2003). Capes: Design Ideas for Renovating, Remodeling, and Building New . Newtown, CT: Taunton. p.  44. ISBN   9781561584369. dormer shed flat gable.
  12. Bradley, Simon, ed. (2010), Pevsner's Architectural Glossary, Yale University Press, p. 80, ISBN   978-0-300-16721-4
  13. 1 2 "Permitted Development Rights". Planning Portal website. . Retrieved 14 October 2013.
  14. "Policy advice note: Garden city settlements" (PDF). TCPA. October 2008. Archived from the original (PDF) on 24 September 2015. Retrieved 14 October 2013.
  15. The Bedside Book of Dormers and Other Delights: A Pictorial Guide to Traditional Architectural Details in Ulster
  16. About Loft Conversions (2008). "Dormer Loft Conversion", About Loft Conversions .