Covering Hounslow
Our coverage around Hounslow (TW3, TW4, TW6) also includes Isleworth (1 miles to the north-east) and Heston.
Homes in London
Terraced houses dominate many London neighbourhoods, so most projects involve shared walls, narrow access and a party wall process. Conservation areas are widespread, and some boroughs have their own mansard and basement guidance.
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.
- Roof removal and new mansard frame
- Staircase, insulation and fit-out
- En-suite, electrics and fire safety
How much does a mansard loft conversion cost in Hounslow?
Typical ranges for mansard loft conversions. Ground conditions, access and specification move the final figure, which we fix in writing before work starts.
| 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 Hounslow?
English projects need planning clearance from the local council, building regulations sign-off from building control, and party wall notices where the work is on or near a shared boundary. We prepare and manage all three.
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.
- Scaffolding and a temporary roof are usually needed.
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.
- Drawings, approvals, written quote. We prepare the design, apply for the approvals it needs, and give you a fixed price in writing.
- We build it. Work follows an agreed programme, with inspections at each stage and a final sign-off.
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 Hounslow?
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 Isleworth
- Mansard loft conversions in Heston
- Mansard loft conversions in Richmond
- Mansard loft conversions in Hanworth
Learn more about mansard loft conversions, or see every project we cover in Hounslow.

