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 Mitcham?
In Mitcham, 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. Prices across London are typically 30% above the UK average for this kind of work, which is reflected in the range for Mitcham. 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:
- Party wall surveyor fees for one or both neighbours
- Total footprint and the amount of glazing
- Steelwork and propping of the existing house
- Access for materials on terraced streets
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 Mitcham?
Here is how the rules work for a wraparound extension 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.
We check this for your address before design work starts, so there are no surprises later.
What we handle
On a typical wraparound extension we handle:
- Foundations and drainage
- Structural engineer’s design for steels and supports
- Underfloor heating option, electrics and plastering
- Party wall notices and surveyor liaison
- Design and planning application
- Walls, roof and glazing
How long does it take?
Build time is typically 12 to 18 weeks on site. Allow time beforehand for drawings and approvals, usually 3 to 4 months.
Building in Mitcham
Space is at a premium in London, so homeowners often build out into the side return or up into the roof rather than move.
We work across Mitcham and neighbouring areas such as Morden, Tooting and Wimbledon. Postcodes we cover in Mitcham include CR4.
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
Drawings and written quote
We prepare the design and give you a written, itemised quote with inclusions and exclusions.
- 03
Approvals
Planning or permitted development confirmation, building regulations and any party wall matters.
- 04
Build and sign-off
We run the build to a written programme and hand over the completion certificate.
Questions about wraparound extensions in Mitcham
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.
How long does a wraparound extension take in Mitcham?
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.
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 much does a wraparound extension cost in Mitcham?
In Mitcham, 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.