Covering Streatham
Our coverage around Streatham (SW16) also includes Mitcham, Brixton and Wimbledon.
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 goes into 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.
- Planning application to local design guidance
- Structural design and party wall process
- Slate cladding and lead-clad dormers
What is the guide price for a mansard loft conversion in Streatham?
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 |
Planning and building rules in Streatham
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 should I think about before starting?
- Council design guides often require natural slate and lead.
- Scaffolding and a temporary roof are usually needed.
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.
- 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.
- 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
Does a mansard need planning permission?
Almost always, because it changes the roof profile.
Will I need party wall agreements?
Very likely, as the work affects the walls shared with both neighbours on a terrace.
Who deals with the council for a project in Streatham?
We do. We prepare the drawings, submit planning or permitted development paperwork if needed, and arrange building control inspections.
Other towns nearby
- Mansard loft conversions in Mitcham
- Mansard loft conversions in Brixton
- Mansard loft conversions in Wimbledon
- Mansard loft conversions in Battersea
Learn more about mansard loft conversions, or see every project we cover in Streatham.

