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 Keynsham?
In Keynsham, a wraparound extension typically costs £2,250–£3,250 per m² of floor area, including VAT at 20% (standard rate). For a typical 28 m² project that is roughly £63,000–£91,000. Prices in the South West sit near the national average for this kind of work, and the range for Keynsham reflects that. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| Smaller project (20 m²) | £45,000–£65,000 |
| Typical project (28 m²) | £63,000–£91,000 |
| Larger project (39 m²) | £88,000–£127,000 |
| Rate per m² | £2,250–£3,250 |
Your quote will depend mainly on:
- Steelwork and propping of the existing house
- Kitchen and flooring specification
- Access for materials on terraced streets
- Party wall surveyor fees for one or both neighbours
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 Keynsham?
The approval route for Keynsham is set by planning law 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
What we take care of:
- Design and planning application
- Removal of internal and external walls
- Building control completion
- Structural engineer’s design for steels and supports
- Party wall notices and surveyor liaison
- Walls, roof and glazing
How long does it take?
The build itself usually takes 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 Keynsham
In parts of the South West, protected landscapes and conservation areas shape what can be built, so materials and roof forms are chosen carefully.
From BS30 outwards, we take on projects throughout Keynsham and the surrounding parts of Gloucestershire.
How it works
- 01
Visit and measured survey
A free visit to understand the project, check access and take measurements.
- 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
Construction and completion
We build, put right any snags and hand over the building control certificate.
Questions about wraparound extensions in Keynsham
Do you build wraparound extensions in Keynsham?
Yes. We build wraparound extensions across Keynsham, including postcodes BS30 and BS31. Every project starts with a free home visit.
How much does a wraparound extension cost in Keynsham?
In Keynsham, a wraparound extension typically costs £2,250–£3,250 per m² of floor area, including VAT at 20% (standard rate). A typical 28 m² project comes to roughly £63,000–£91,000. 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.
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.
How long does it take to build?
Around 12 to 18 weeks on site after approvals. Design, planning and party wall matters usually take 3 to 4 months beforehand.