Dormer window
A dormer is a small roofed structure that projects outwards from the main pitched roof of a building. Dormers can be included in the original construction of a building or added on subsequently.
Dormers are becoming more common in homes as they can help create extra headroom in spaces that may otherwise be too small or too low for habitation. They enable the creation of rooms in the roof or loft without needing to construct a new storey. Dormers will typically have dormer windows set into them to allow light and ventilation.
There are a number of different types of dormers including:
Box roof/flat roof: The plane of the roof is horizontal. This type of dormer provides the most space and floor area inside the building.
Gable: These have a gable roof, with the front of the dormer being flat with a pitched roof and vertical sides.
Hip roof: The roof comprises of three sloping panels that meet at the ridge.
Arched/eyebrow: This is similar to the hipped dormer but has an arch or curve which allows it to blend in to the existing roof.
The insertion of dormer windows as part of a loft conversion does not normally require planning permission is not normally required. However, If the roof space is altered or extended and it exceeds specified limits and conditions, permission may be necessary. It may also be necessary to obtain permission within conservation areas, National Parks, Areas of Outstanding Natural Beauty or the Broads, or if the building is listed.
Dormer windows may require building regulations approval.
[edit] Find out more
[edit] Related articles on Designing Buildings Wiki.
- A-frame house.
- Alcove.
- Building regulations.
- Conical roof slating.
- Conservation area.
- Cool roof.
- Domestic roof.
- Domestic windows.
- Green roof.
- Listed building.
- Loft conversion.
- Long span roof.
- Roof gardens.
- Roof insulation.
- Window parts.
[edit] External references
Featured articles and news
IHBC book review: Charles Barry’s monumental struggle to rebuild the Houses of Parliament.
Read about RSHP's British Museum extension which has been shortlisted for the 2017 Stirling Prize.
Read our introductory article to building a house extension.
More updates from DCMS about the large-scale testing of cladding systems and the number of buildings affected.
UandI secure resolution to grant planning consent for major new regeneration project.
Infrastructure and the historic environment
IHBC article considers how heritage is dealt with when infrastructure schemes are authorised.
It was the tallest structure in the world for 3,800 years, but to this day the exact construction techniques are a mystery.
Shortlist for the industry's most coveted award announced.
Government responds to Mark Farmer's review of industry, rejecting the call for a levy on clients.
Peter Hansford to examine what wider lessons can be learned from the fire.
Every project is subject to uncertainty. How can construction better understand uncertainty for performance improvement?
MAD Architects reveal their designs for a futuristic campus for electric car manufacturer.
Homebuyers could borrow more with better forecasting of energy bills, according to industry consortium's new report.
Grenfell Tower articles updated daily
