Mansard loft conversions in Heston

Covering Heston

Our coverage around Heston (TW5) also includes Hounslow, Isleworth and Southall.

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 does a mansard loft conversion involve?

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
Staircase, insulation and fit-out
En-suite, electrics and fire safety

How much does a mansard loft conversion cost in Heston?

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

How is a mansard loft conversion approved in Heston?

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. Many councils publish guidance on mansard design.

What should Heston homeowners check first?

A mansard nearly always involves party walls on both sides of a terrace.
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.
Free site visit. We measure up, look at access, drains and the structure, and talk through options and budget.
Drawings, approvals, written quote. We prepare the design, apply for the approvals it needs, and give you a fixed price in writing.
Construction and completion. One site lead co-ordinates every trade through to the building control certificate.

Your questions answered

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.

Why choose a mansard over a dormer?

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

Do you work in Heston?

Yes. Heston is within our coverage for mansard loft conversions, along with nearby Hounslow and Isleworth.

Mansard loft conversions near Heston

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