Mansard loft conversions in Barnes

Covering Barnes

Our coverage around Barnes (SW13) also includes Chiswick (1 miles to the north) and Putney.

Homes in London

London projects often mean working on period terraces with neighbours on both sides, tight access through the house and conservation area controls, so careful planning and party wall work matter as much as the build.

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.

Structural design and party wall process
Roof removal and new mansard frame
Slate cladding and lead-clad dormers

What will a mansard loft conversion cost?

What mansard loft conversions typically cost. These are guide ranges; the written quote for your house replaces them.

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 Barnes?

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 affect a mansard loft conversion?

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

What happens after I enquire?

Start with a conversation. A short call or the online form is enough for us to understand what you want to build.
We visit and measure. A surveyor checks the house, the boundaries and the ground, and discusses what is realistic.
Design and fixed price. You get drawings and a written price for the agreed specification before anything is ordered.
Construction and completion. One site lead co-ordinates every trade through to the building control certificate.

What people ask before starting

How much does a mansard loft conversion cost?

Typically £65,000 to £110,000 including VAT, depending on whether one or both roof slopes are rebuilt.

Will I need party wall agreements?

Very likely, as the work affects the walls shared with both neighbours on a terrace.

Who deals with the council for a project in Barnes?

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 Barnes.