This is general guidance based on standard permitted development rights in England. Rules differ for listed buildings, conservation areas, and properties with Article 4 directions. Always confirm with your local planning authority before starting work.
Do I Need Planning Permission for a Roof Windows (Velux)?
Installing roof windows (also known as Velux windows or skylights) into an existing roof slope. Roof windows are a popular way to bring light into loft spaces without the cost of a full dormer.
The General Position
This project is usually allowed under permitted development rights without needing to apply for planning permission, provided certain conditions and limits are met.
Generally permitted under Part 1, Class C of the GPDO. Roof windows are permitted provided they do not protrude more than 150mm beyond the plane of the roof slope. Side-facing windows at upper-floor level must be obscure glazed and non-opening below 1.7m from the floor.
Conditions and Requirements
- 1Must not protrude more than 150mm beyond the existing roof plane
- 2Side-facing windows (on a wall or roof slope forming a side elevation) must be obscure glazed and non-opening below 1.7m from the floor
- 3The window must not result in the roof exceeding the existing ridge height
Size and Dimension Limits
- Protrusion: maximum 150mm beyond the roof plane
- No specific size limit for individual windows
When Permitted Development Does Not Apply
- In conservation areas, roof windows on the principal or highway-facing elevation may not be PD
- Listed buildings require listed building consent
- Multiple roof windows may cumulatively change the character of the roof, potentially requiring PP
What About Building Regulations?
Building Regulations may apply depending on the structural alteration to the roof. Covers structural integrity of the roof after cutting rafters, thermal performance (Part L), and fire safety (means of escape if the room is a habitable loft). A FENSA-registered installer or building control notification is needed for the glazing.
Building regulations are separate from planning permission. You may need both, one, or neither depending on your project. Building regulations cover the safety and quality of building work, including structural integrity, fire safety, insulation, ventilation, and drainage.
How to Apply for Planning Permission
Check if you need permission
Review the permitted development rules above. If in doubt, contact your council or apply for a Lawful Development Certificate.
Prepare your application
You will need scaled drawings, a site plan, and a completed application form. An architect or planning consultant can help with this.
Submit to your local council
Applications can be submitted online via the Planning Portal or directly to your council. Select your council below for a direct link.
Wait for a decision
8 weeks for householder planning applications if PP is needed..
Application cost: £258.
What Happens If I Build Without Permission?
Low risk for standard roof windows within PD limits. Enforcement may occur if windows overlook neighbouring properties without being obscure glazed where required, or in conservation areas without consent.
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Select Your Council
Choose your local council for guidance specific to your area, including links to apply and whether your council has conservation areas or Article 4 directions that could affect your project.
London
South East
South West
East of England
East Midlands
West Midlands
North East
North West
Yorkshire and the Humber
CA = has conservation areas. A4 = has Article 4 directions. These may restrict your permitted development rights.