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 Clapham?
In Clapham, 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. The guide for Clapham reflects typical costs in London, roughly 30% above the UK-wide figure. 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 |
Your quote will depend mainly on:
- Access for materials on terraced streets
- Total footprint and the amount of glazing
- Steelwork and propping of the existing house
- Drainage changes
Your exact price depends on the survey and drawings. The guide price tool gives a quick range in the meantime.
Do you need planning permission for a wraparound extension in Clapham?
The approval route for Clapham is set by planning law 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.
Where work involves a shared wall, building on the boundary, or digging foundations within 3 metres of a neighbour’s building and deeper than its foundations (or within 6 metres for deeper work), the Party Wall etc. Act 1996 applies and notices must be served before work starts.
At the survey we check your house’s planning history and any restrictions, and tell you which route applies.
What we handle
The work we manage on a wraparound extension:
- Building control completion
- Removal of internal and external walls
- Underfloor heating option, electrics and plastering
- Walls, roof and glazing
- Foundations and drainage
- Structural engineer’s design for steels and supports
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 Clapham
Victorian and Edwardian terraces dominate many London streets, which is why side return, wraparound and mansard projects are so common here.
From SW4 outwards, we take on projects throughout Clapham and the surrounding parts of Greater London.
How it works
- 01
Free visit
We look at the property, talk through what you want and measure up. There is no charge and no obligation.
- 02
Design and pricing
Design options, then a fixed quote based on the chosen drawings and specification.
- 03
Approvals in place
We handle planning, building control and neighbour notices before work starts.
- 04
Build and handover
Work follows the agreed programme, with inspections along the way and a completion certificate at the end.
Questions about wraparound extensions in Clapham
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.
How much does a wraparound extension cost in Clapham?
In Clapham, 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.
Can we keep a separate living room?
Yes. Many clients keep the front room separate and open up only the back of the house.
How long does a wraparound extension take in Clapham?
Typically 12 to 18 weeks on site. Design and approvals beforehand usually take 3 to 4 months.
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.