Covering Brixton
Alongside Brixton, we also cover Peckham, Battersea (2 miles to the west) and Streatham.
Homes in London
Much of London’s housing is Victorian and Edwardian terraces, which is why side return extensions, rear dormers and mansards are so common. Many streets are in conservation areas, and several boroughs use Article 4 directions that remove some permitted development rights.
What is a mansard loft conversion?
A mansard loft conversion replaces one or both slopes of a roof with a near-vertical wall, typically at 70 degrees, with small dormer windows set into it. It creates almost a full extra storey and is common on terraced houses in towns and cities, particularly in London.
- Planning application to local design guidance
- Staircase, insulation and fit-out
- En-suite, electrics and fire safety
How much should I budget for a mansard loft conversion?
Guide prices for mansard loft conversions, including VAT where it applies. Your fixed price is confirmed in writing after the survey.
| Mansard loft conversions | Guide price incl. VAT |
|---|---|
| Rear mansard | £65,000 to £85,000 |
| Front and rear (double) mansard | £80,000 to £110,000 |
Do you need permission for a mansard loft conversion in Brixton?
Projects in England go through two separate checks. Planning (or confirmation that the work is permitted development) comes from the district, borough or unitary council, and building regulations approval comes from the council’s building control team or a registered building control approver. Where work touches a shared wall or digs near a neighbour’s foundations, the Party Wall etc. Act 1996 applies.
Mansard conversions change the shape of the roof significantly, so they usually need planning permission in England.
What can change the price or programme?
- The roof is open for longer than with a dormer, so weather protection matters.
- Scaffolding and a temporary roof are usually needed.
How does the project run?
- Tell us about the project. Call, use the guide price tool or send the form with a few photos and a postcode.
- We visit and measure. A surveyor checks the house, the boundaries and the ground, and discusses what is realistic.
- Drawings, approvals, written quote. We prepare the design, apply for the approvals it needs, and give you a fixed price in writing.
- Build and hand over. Our teams build to the programme, building control inspects, and you get the completion paperwork at the end.
Mansard loft conversions: common questions
Does a mansard need planning permission?
Almost always, because it changes the roof profile.
How long does a mansard take?
Around 10 to 14 weeks on site after planning approval.
How do I get a price for mansard loft conversions in Brixton?
Use the guide price tool for a ballpark figure, then book a visit for a fixed written price for the agreed specification.
Other towns nearby
- Mansard loft conversions in Peckham
- Mansard loft conversions in Battersea
- Mansard loft conversions in Streatham
- Mansard loft conversions in Chelsea
Learn more about mansard loft conversions, or see every project we cover in Brixton.

