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 Sevenoaks?
In Sevenoaks, a wraparound extension typically costs £2,450–£3,600 per m² of floor area, including VAT at 20% (standard rate). For a typical 28 m² project that is roughly £68,500–£101,000. We start from a UK-wide guide and adjust it for the South East, where labour and materials are typically about 12% above average. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| Smaller project (20 m²) | £49,000–£72,000 |
| Typical project (28 m²) | £68,500–£101,000 |
| Larger project (39 m²) | £95,500–£140,500 |
| Rate per m² | £2,450–£3,600 |
The biggest cost drivers are:
- Access for materials on terraced streets
- Kitchen and flooring specification
- Total footprint and the amount of glazing
- Party wall surveyor fees for one or both neighbours
For a figure based on your own measurements, try the guide price tool, then book a free home visit for a fixed quote.
Do you need planning permission for a wraparound extension in Sevenoaks?
Whether you need planning permission depends on your house and its location 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
Handled as part of most wraparound extensions:
- Structural engineer’s design for steels and supports
- Foundations and drainage
- Party wall notices and surveyor liaison
- Building control completion
- Underfloor heating option, electrics and plastering
- Walls, roof and glazing
How long does it take?
Allow 12 to 18 weeks on site. Allow time beforehand for drawings and approvals, usually 3 to 4 months.
Building in Sevenoaks
The South East has a broad mix of housing, from Victorian terraces in the towns to post-war semis and newer estates, so extension types vary street by street.
We work across Sevenoaks and neighbouring areas such as Tonbridge, Orpington and Swanley. Postcodes we cover in Sevenoaks include TN13.
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
Construction and completion
We build, put right any snags and hand over the building control certificate.
Questions about wraparound extensions in Sevenoaks
How much does a wraparound extension cost in Sevenoaks?
In Sevenoaks, a wraparound extension typically costs £2,450–£3,600 per m² of floor area, including VAT at 20% (standard rate). A typical 28 m² project comes to roughly £68,500–£101,000. Your fixed price depends on the survey and drawings.
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.
Who approves a wraparound extension in Sevenoaks?
Planning matters in Sevenoaks go to the council covering your address, and the work needs building control approval. We prepare and submit the applications for you.
Can we keep a separate living room?
Yes. Many clients keep the front room separate and open up only the back of the house.
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.
