Covering Bletchley
We work in Bletchley (MK3) and the places around it, including Milton Keynes, Leighton Buzzard and Buckingham.
Homes in the South East
Housing across the South East mixes inter-war semis, post-war estates and older cottages in villages and market towns, so rear and side extensions, hip-to-gable lofts and garage conversions all come up regularly.
What is a mansard loft conversion?
A mansard loft conversion replaces one or both slopes of a roof with a near-vertical wall, typically at 70 degrees, with small dormer windows set into it. It creates almost a full extra storey and is common on terraced houses in towns and cities, particularly in London.
- Roof removal and new mansard frame
- Slate cladding and lead-clad dormers
- Staircase, insulation and fit-out
What will a mansard loft conversion cost?
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 |
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. Many councils publish guidance on mansard design.
What can affect a mansard loft conversion?
- A mansard nearly always involves party walls on both sides of a terrace.
- Scaffolding and a temporary roof are usually needed.
What are the steps?
- Send us the details. Give us a postcode, a rough idea of size and some photos, by phone, form or the guide price tool.
- We visit and measure. A surveyor checks the house, the boundaries and the ground, and discusses what is realistic.
- 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.
Questions about a mansard loft conversion in Bletchley
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.
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 Bletchley?
Use the guide price tool for a ballpark figure, then book a visit for a fixed written price for the agreed specification.
Also covering
- Mansard loft conversions in Milton Keynes
- Mansard loft conversions in Leighton Buzzard
- Mansard loft conversions in Buckingham
- Mansard loft conversions in Dunstable
Learn more about mansard loft conversions, or see every project we cover in Bletchley.

