Covering Carshalton
Our coverage around Carshalton (SM5) also includes Sutton (2 miles to the south-west) and Mitcham.
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 side return extension?
Side returns are small in area but heavy in detail: party walls, a glazed roof, and steelwork to take out the original back wall. We design the roof for light and drainage, agree the party wall process early, and keep the work tidy because access is often through the house.
- Drainage and new gully positions
- Underfloor heating ready screed if wanted
- Plastering and making good to the old house
What is the guide price for a side return extension in Carshalton?
Typical ranges for side return extensions. Ground conditions, access and specification move the final figure, which we fix in writing before work starts.
| Side return extensions | Guide price incl. VAT |
|---|---|
| Standard specification | £3,350 to £3,700 per m² |
| Good specification | £3,700 to £4,150 per m² |
| High specification | £4,150 to £4,550 per m² |
Planning and building rules in Carshalton
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.
In England a single-storey rear extension can often go ahead under permitted development: up to 3 m deep on an attached house or 4 m on a detached one, no higher than 4 m, with eaves no higher than 3 m within 2 m of a boundary.
What should Carshalton homeowners check first?
- Most side returns touch a shared boundary, so the Party Wall etc. Act 1996 usually applies in England and Wales.
- Many terraces sit in conservation areas, where side extensions need planning permission.
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.
- Design and fixed price. You get drawings and a written price for the agreed specification before anything is ordered.
- Construction and completion. One site lead co-ordinates every trade through to the building control certificate.
Your questions answered
Does a side return need planning permission?
In England it can be permitted development if it is single storey, no higher than 4 m and no wider than half the original house. Conservation areas are the main exception.
Is a glazed roof too hot in summer?
Modern solar-control glass and a mix of glazed and solid roof keep it comfortable. We advise on the balance during design.
Can you visit a house in Carshalton to quote?
Yes. After a short call we arrange a site visit to measure up and agree what the design needs to do, then send a written price.
Side return extensions near Carshalton
- Side return extensions in Sutton
- Side return extensions in Mitcham
- Side return extensions in Morden
- Side return extensions in Croydon
Learn more about side return extensions, or see every project we cover in Carshalton.

