What is a wraparound extension?
A wraparound extension combines a side return and a rear extension into one L-shaped addition. It gives the largest possible ground floor, often creating an open-plan kitchen, dining and living space across the whole width of the house.
How much does a wraparound extension cost in Carshalton?
In Carshalton, a wraparound extension typically costs £2,850–£4,150 per m² of floor area, including VAT at 20% (standard rate). For a typical 28 m² project that is roughly £80,000–£116,000. That range is adjusted for London, where domestic building work typically costs around 30% above the national average. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| Smaller project (20 m²) | £57,000–£83,000 |
| Typical project (28 m²) | £80,000–£116,000 |
| Larger project (39 m²) | £111,000–£162,000 |
| Rate per m² | £2,850–£4,150 |
What moves the price most:
- Access for materials on terraced streets
- Kitchen and flooring specification
- Party wall surveyor fees for one or both neighbours
- Steelwork and propping of the existing house
A guide range is only a starting point: the guide price tool gives an instant figure for your size, and a free survey turns it into a fixed quote.
Do you need planning permission for a wraparound extension in Carshalton?
Whether you need planning permission depends on your house and its location in England. In England a wraparound extension combines side and rear elements, which normally takes it outside permitted development, so a householder planning application is made.
Building regulations approval comes from the council’s building control service or a registered building control approver. The work is inspected at key stages, such as foundations, drainage and insulation, and a completion certificate is issued at the end.
At the survey we check your house’s planning history and any restrictions, and tell you which route applies.
What we handle
What we take care of:
- Building control completion
- Underfloor heating option, electrics and plastering
- Foundations and drainage
- Party wall notices and surveyor liaison
- Structural engineer’s design for steels and supports
- Design and planning application
How long does it take?
The build itself usually takes 12 to 18 weeks on site. Allow time beforehand for drawings and approvals, usually 3 to 4 months.
Building in Carshalton
Space is at a premium in London, so homeowners often build out into the side return or up into the roof rather than move.
If your home is in Carshalton or close by in Sutton, Wallington and Mitcham, a free home visit is the first step.
How it works
- 01
Visit and measured survey
A free visit to understand the project, check access and take measurements.
- 02
Design and fixed quote
Drawings, structural calculations and an itemised, fixed price for the agreed specification.
- 03
Approvals
Planning or permitted development confirmation, building regulations and any party wall matters.
- 04
Construction and completion
We build, put right any snags and hand over the building control certificate.
Questions about wraparound extensions in Carshalton
How much does a wraparound extension cost in Carshalton?
In Carshalton, a wraparound extension typically costs £2,850–£4,150 per m² of floor area, including VAT at 20% (standard rate). A typical 28 m² project comes to roughly £80,000–£116,000. Your fixed price depends on the survey and drawings.
Will both neighbours be affected?
Usually only the neighbour on the side return side, but rear foundations near either boundary can trigger party wall notices.
How long does a wraparound extension take in Carshalton?
Typically 12 to 18 weeks on site. Design and approvals beforehand usually take 3 to 4 months.
Does a wraparound extension need planning permission?
Almost always. Combining side and rear elements usually goes beyond permitted development limits, so a householder planning application is normally made.
Is a wraparound worth it?
It gives the biggest ground-floor space without going upwards. Whether it adds value depends on your street and house, so we suggest checking local sale prices before committing.