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 Roof Windows (Velux) in City of London?
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.
Planning in City of London
96%
of planning applications granted
84%
decided within the statutory or agreed time
In the year to December 2025, City of London decided 448 planning applications.
Planning statistics: MHCLG planning application statistics, the year to December 2025. Conservation area and Article 4 data: planning.data.gov.uk, © Historic England / Crown copyright. Open Government Licence v3.0.
Important: Additional Restrictions May Apply in City of London
City of London has 28 conservation areas. These include Bank, Barbican and Golden Lane, Bishopsgate, Bow Lane, Brewery, Chancery Lane. If your property is in a conservation area, some or all permitted development rights may be restricted. For example, you may need planning permission for changes that would normally be permitted, including alterations to the roof, cladding, or extensions visible from a public highway.
City of London has 1 recorded Article 4 direction. Article 4 directions remove specific permitted development rights in defined areas. If your property is covered by an Article 4 direction, you may need planning permission for work that would normally be permitted. Contact City of London planning department to check whether an Article 4 direction applies to your property.
Check with City of London planning department before starting work to confirm whether your property is affected by any special designations.
Permitted Development Rules for Roof Windows (Velux)
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
- 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 approval is likely required
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. Even if your project is permitted development, you may still need building regulations approval. Contact City of London building control or use an approved inspector.
How to Apply in City of London
If you need planning permission for your roof windows (velux), you can apply through City of London's planning department or via the national Planning Portal.
If your project is permitted development and you want written confirmation, you can apply for a Lawful Development Certificate (LDC) from City of London. This provides proof that your project does not need planning permission, which can be helpful when selling your property.
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.
Frequently Asked Questions
Do I need planning permission for roof windows (velux) in City of London?
Does roof windows (velux) in City of London need building regulations?
How do I apply for planning permission in City of London?
How long does planning permission take in City of London?
What percentage of planning applications does City of London approve?
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