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 Bermondsey?
In Bermondsey, 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 |
The main things that change the cost:
- Steelwork and propping of the existing house
- Total footprint and the amount of glazing
- Party wall surveyor fees for one or both neighbours
- 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 Bermondsey?
Before anything is built in Bermondsey, 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.
Our first visit includes a check of your planning history, so you know the route before paying for drawings.
What we handle
On a typical wraparound extension we handle:
- Underfloor heating option, electrics and plastering
- Removal of internal and external walls
- Design and planning application
- Building control completion
- Foundations and drainage
- Walls, roof and glazing
How long does it take?
Build time is typically 12 to 18 weeks on site. Design and approvals come first and typically take 3 to 4 months, depending on the approval route.
Building in Bermondsey
Many London boroughs have conservation areas and detailed design guides, so early design advice saves time at the planning stage.
Our Bermondsey coverage includes postcode districts SE1 and SE16, and we also work in nearby places such as Peckham, Westminster and Greenwich.
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 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 Bermondsey
What about the old back addition?
The side wall of the back addition is usually removed and replaced with a steel beam, so the old kitchen joins the new space.
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 long does a wraparound extension take in Bermondsey?
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 Bermondsey?
In Bermondsey, 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.
