Mansard loft conversions in Harrow

Covering Harrow

Alongside Harrow, we also cover Brent, Wembley (2 miles to the south-east) and Northolt.

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 goes into a mansard loft conversion?

Mansards are a bigger structural job than other conversions because the roof is largely rebuilt. They normally need planning permission, and many councils have design guides setting the angle, materials and window style. We prepare the design to those guides and build in slate, lead and timber or approved alternatives.

Planning application to local design guidance
Structural design and party wall process
Slate cladding and lead-clad dormers

What is the guide price for a mansard loft conversion in Harrow?

Use these ranges to budget for mansard loft conversions; the survey turns them into a fixed price for the agreed specification.

Mansard loft conversions	Guide price incl. VAT
Rear mansard	£65,000 to £85,000
Front and rear (double) mansard	£80,000 to £110,000

Planning and building rules in Harrow

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 should I think about before starting?

The roof is open for longer than with a dormer, so weather protection matters.
Council design guides often require natural slate and lead.

From first call to completion

Send us the details. Give us a postcode, a rough idea of size and some photos, by phone, form or the guide price tool.
Survey at your house. We look at the existing structure, services and access, and agree what the design needs to achieve.
Price and paperwork. The design is priced line by line, and we submit the planning and building control applications.
Build and hand over. Our teams build to the programme, building control inspects, and you get the completion paperwork at the end.

Your questions answered

Does a mansard need planning permission?

Almost always, because it changes the roof profile.

Why choose a mansard over a dormer?

A mansard gives more usable space and often fits a street better where neighbours already have one.

Who deals with the council for a project in Harrow?

We do. We prepare the drawings, submit planning or permitted development paperwork if needed, and arrange building control inspections.

Mansard loft conversions in nearby towns

Learn more about mansard loft conversions, or see every project we cover in Harrow.