Covering Becontree
Becontree is about 11 miles east of London. We also cover Dagenham (2 miles to the east), Barking and Ilford.
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 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.
- Structural design and party wall process
- Roof removal and new mansard frame
- En-suite, electrics and fire safety
How much does a mansard loft conversion cost in Becontree?
Use these ranges to budget for mansard loft conversions; the survey turns them into a fixed price for the agreed specification.
| 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 Becontree?
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 I think about before starting?
- Council design guides often require natural slate and lead.
- Scaffolding and a temporary roof are usually needed.
What happens after I enquire?
- 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.
- Price and paperwork. The design is priced line by line, and we submit the planning and building control applications.
- Construction and completion. One site lead co-ordinates every trade through to the building control certificate.
What people ask before starting
Does a mansard need planning permission?
Almost always, because it changes the roof profile.
Why choose a mansard over a dormer?
A mansard gives more usable space and often fits a street better where neighbours already have one.
How do I get a price for mansard loft conversions in Becontree?
Use the guide price tool for a ballpark figure, then book a visit for a fixed written price for the agreed specification.
Mansard loft conversions in nearby towns
- Mansard loft conversions in Dagenham
- Mansard loft conversions in Barking
- Mansard loft conversions in Ilford
- Mansard loft conversions in Romford
Learn more about mansard loft conversions, or see every project we cover in Becontree.

