Covering Barnet
Barnet is about 10 miles north of London. We also cover Potters Bar (3 miles to the north), Borehamwood and Finchley.
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 is included in a mansard loft conversion in Barnet?
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
- Roof removal and new mansard frame
- Slate cladding and lead-clad dormers
What will a mansard loft conversion cost?
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 Barnet?
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. Many councils publish guidance on mansard design.
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.
How does the project run?
- Tell us about the project. Call, use the guide price tool or send the form with a few photos and a postcode.
- 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.
- Build and hand over. Our teams build to the programme, building control inspects, and you get the completion paperwork at the end.
Questions about a mansard loft conversion in Barnet
How long does a mansard take?
Around 10 to 14 weeks on site after planning approval.
Why choose a mansard over a dormer?
A mansard gives more usable space and often fits a street better where neighbours already have one.
Can you visit a house in Barnet to quote?
Yes. After a short call we arrange a site visit to measure up and agree what the design needs to do, then send a written price.
Mansard loft conversions in nearby towns
- Mansard loft conversions in Potters Bar
- Mansard loft conversions in Borehamwood
- Mansard loft conversions in Finchley
- Mansard loft conversions in Muswell Hill
Learn more about mansard loft conversions, or see every project we cover in Barnet.

