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 Hampstead?
In Hampstead, 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 Hampstead. 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 main things that change the cost:
- Total footprint and the amount of glazing
- Party wall surveyor fees for one or both neighbours
- Steelwork and propping of the existing house
- Kitchen and flooring specification
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 Hampstead?
Before anything is built in Hampstead, we confirm which approvals apply 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
What we take care of:
- Foundations and drainage
- Design and planning application
- Structural engineer’s design for steels and supports
- Building control completion
- Removal of internal and external walls
- Party wall notices and surveyor liaison
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 Hampstead
Space is at a premium in London, so homeowners often build out into the side return or up into the roof rather than move.
From NW3 outwards, we take on projects throughout Hampstead and the surrounding parts of Greater London.
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 handover
Work follows the agreed programme, with inspections along the way and a completion certificate at the end.
Questions about wraparound extensions in Hampstead
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.
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.
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 much does a wraparound extension cost in Hampstead?
In Hampstead, 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.
How long does a wraparound extension take in Hampstead?
Typically 12 to 18 weeks on site. Design and approvals beforehand usually take 3 to 4 months.