Mansard loft conversions in Carshalton

Covering Carshalton

Our coverage around Carshalton (SM5) also includes Sutton (2 miles to the south-west) and Mitcham.

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.

Roof removal and new mansard frame
Staircase, insulation and fit-out
En-suite, electrics and fire safety

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

What approvals does a mansard loft conversion need in England?

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?

A mansard nearly always involves party walls on both sides of a terrace.
The roof is open for longer than with a dormer, so weather protection matters.

How does the project run?

Send us the details. Give us a postcode, a rough idea of size and some photos, by phone, form or the guide price tool.
Free site visit. We measure up, look at access, drains and the structure, and talk through options and budget.
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.

Questions about a mansard loft conversion in Carshalton

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.

Does a mansard need planning permission?

Almost always, because it changes the roof profile.

How do I get a price for mansard loft conversions in Carshalton?

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

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