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 Tonbridge?
In Tonbridge, 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. Building costs in the South East run about 12% above the UK average, and the figures for Tonbridge are adjusted to reflect that. 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 |
Your quote will depend mainly on:
- Kitchen and flooring specification
- Party wall surveyor fees for one or both neighbours
- Steelwork and propping of the existing house
- Drainage changes
Use the guide price tool to see how size and specification change the figure, then ask for a written, itemised quote.
Do you need planning permission for a wraparound extension in Tonbridge?
Before anything is built in Tonbridge, 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
The work we manage on a wraparound extension:
- Underfloor heating option, electrics and plastering
- Party wall notices and surveyor liaison
- Design and planning application
- Structural engineer’s design for steels and supports
- Removal of internal and external walls
- Building control completion
How long does it take?
Expect 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 Tonbridge
Commuter towns across the South East have many 1930s and post-war semis that suit rear extensions and hip-to-gable loft conversions.
From TN9 outwards, we take on projects throughout Tonbridge and the surrounding parts of Kent.
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 in place
We handle planning, building control and neighbour notices before work starts.
- 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 Tonbridge
Can we keep a separate living room?
Yes. Many clients keep the front room separate and open up only the back of the house.
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.
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 Tonbridge?
In Tonbridge, 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.
How long does a wraparound extension take in Tonbridge?
Typically 12 to 18 weeks on site. Design and approvals beforehand usually take 3 to 4 months.
