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 Greenford?
In Greenford, 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 Greenford. 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 |
The biggest cost drivers are:
- Access for materials on terraced streets
- Steelwork and propping of the existing house
- Total footprint and the amount of glazing
- Drainage changes
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 Greenford?
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
The work we manage on a wraparound extension:
- Party wall notices and surveyor liaison
- Foundations and drainage
- Walls, roof and glazing
- Design and planning application
- Underfloor heating option, electrics and plastering
- Building control completion
How long does it take?
The build itself usually takes 12 to 18 weeks on site. Before that, surveys, drawings and approvals usually take 3 to 4 months, longer if the council asks for changes.
Building in Greenford
Space is at a premium in London, so homeowners often build out into the side return or up into the roof rather than move.
Our Greenford coverage includes postcode districts UB6, and we also work in nearby places such as Northolt, Southall and Ealing.
How it works
- 01
Visit and measured survey
A free visit to understand the project, check access and take measurements.
- 02
Design and pricing
Design options, then a fixed quote based on the chosen drawings and specification.
- 03
Permissions sorted
Applications, building control and neighbour arrangements, all before the start date.
- 04
Build and sign-off
We run the build to a written programme and hand over the completion certificate.
Questions about wraparound extensions in Greenford
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.
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.
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 Greenford?
Typically 12 to 18 weeks on site. Design and approvals beforehand usually take 3 to 4 months.
How much does a wraparound extension cost in Greenford?
In Greenford, 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.
