Covering Northampton
Our coverage around Northampton (NN1) also includes Wellingborough, Towcester and Daventry.
Homes in the East Midlands
Across the East Midlands you find everything from city terraces to modern estates and stone villages, so the right extension depends a lot on the street and the materials around it.
What do you get with 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 is the guide price for a mansard loft conversion in Northampton?
Indicative costs for mansard loft conversions. London and the South East usually sit towards the top of each range.
| 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 Northampton?
In England we deal with the council’s planning team for permission or a lawful development certificate, with building control (the council or a registered building control approver) for inspections, and with neighbours under the Party Wall etc. Act 1996 where it applies.
Mansard conversions change the shape of the roof significantly, so they usually need planning permission in England.
What can change the price or programme?
- 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
- Start with a conversation. A short call or the online form is enough for us to understand what you want to build.
- 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.
- Build and hand over. Our teams build to the programme, building control inspects, and you get the completion paperwork at the end.
What people ask before starting
Why choose a mansard over a dormer?
A mansard gives more usable space and often fits a street better where neighbours already have one.
Will I need party wall agreements?
Very likely, as the work affects the walls shared with both neighbours on a terrace.
Do you work in Northampton?
Yes. Northampton is within our coverage for mansard loft conversions, along with nearby Wellingborough and Towcester.
Also covering
- Mansard loft conversions in Wellingborough
- Mansard loft conversions in Towcester
- Mansard loft conversions in Daventry
- Mansard loft conversions in Rushden
Learn more about mansard loft conversions, or see every project we cover in Northampton.

