Covering Carshalton
Alongside Carshalton, we also cover Sutton, Mitcham (2 miles to the north) and Morden.
Homes in London
Much of London’s housing is Victorian and Edwardian terraces, which is why side return extensions, rear dormers and mansards are so common. Many streets are in conservation areas, and several boroughs use Article 4 directions that remove some permitted development rights.
What do you get with a garden annexe?
We design annexes as permanent buildings with proper foundations, insulation and services, and we prepare the planning case showing how the annexe will be used as part of the main home. Connections for water, drainage and power are planned from the start.
- Design and planning application
- Foundations and drainage connections
- Accessible design options for older relatives
What will a garden annexe cost?
Use these ranges to budget for garden annexes; the survey turns them into a fixed price for the agreed specification.
| Garden annexes | Guide price incl. VAT |
|---|---|
| Standard specification | £2,400 to £2,900 per m² |
| Good specification | £2,900 to £3,400 per m² |
| High specification | £3,400 to £3,900 per m² |
Planning and building rules in Carshalton
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.
A self-contained annexe used for sleeping and living normally needs planning permission in England.
What can affect a garden annexe?
- The annexe normally has to remain part of the main household, not let as a separate home.
- Drainage may need a pump if the garden falls away from the sewer.
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.
- 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.
Questions about a garden annexe in Carshalton
How much does a garden annexe cost?
Around £2,400 to £3,900 per square metre including VAT, depending on finish and services.
Can you make it wheelchair accessible?
Yes. Level access, wider doors and a level-access shower can be designed in from the start.
Who deals with the council for a project in Carshalton?
We do. We prepare the drawings, submit planning or permitted development paperwork if needed, and arrange building control inspections.
Garden annexes near Carshalton
Learn more about garden annexes, or see every project we cover in Carshalton.

