What is a barn conversion?
A barn conversion turns an agricultural or rural building into a home while keeping its character: the brick or stone walls, roof timbers and large openings. It involves structural repair, insulation, new services and often a new floor slab.
How much does a barn conversion cost in Sunbury-on-Thames?
In Sunbury-on-Thames, a barn conversion typically costs £2,000–£3,350 per m² of floor area, including VAT at usually 5% (reduced rate for creating a new dwelling). For a typical 150 m² project that is roughly £300,000–£502,500. Prices across the South East are typically 12% above the UK average for this kind of work, which is reflected in the range for Sunbury-on-Thames. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| Smaller project (105 m²) | £210,000–£352,000 |
| Typical project (150 m²) | £300,000–£502,500 |
| Larger project (210 m²) | £420,000–£703,500 |
| Rate per m² | £2,000–£3,350 |
What moves the price most:
- Glazing and finishes
- Planning conditions and ecology
- Services and drainage
- Condition of the existing structure
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 barn conversion in Sunbury-on-Thames?
Whether you need planning permission depends on your house and its location in England. In England converting an agricultural building into a home needs either full planning permission or prior approval under Class Q of the permitted development rules, which limits floor space and the number of homes. Listed barns also need listed building consent.
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 barn conversion:
- Building control completion
- Insulation that respects the existing fabric
- Services, drainage and septic or treatment plant
- Structural repairs and new floor slab
- Planning or prior approval application
- Ecology and bat survey coordination
How long does it take?
Expect 6 to 12 months on site depending on condition. Before that, surveys, drawings and approvals usually take 4 to 9 months, longer if the council asks for changes.
Building in Sunbury-on-Thames
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.
If your home is in Sunbury-on-Thames or close by in Walton-on-Thames, Ashford and Weybridge, a free home visit is the first step.
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
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 barn conversions in Sunbury-on-Thames
Is VAT reduced on a barn conversion?
Usually yes. Converting a non-residential building into a dwelling normally qualifies for the reduced 5% VAT rate on building work. Our guide prices assume this rate.
How much does a barn conversion cost in Sunbury-on-Thames?
In Sunbury-on-Thames, a barn conversion typically costs £2,000–£3,350 per m² of floor area, including VAT at usually 5% (reduced rate for creating a new dwelling). A typical 150 m² project comes to roughly £300,000–£502,500. Your fixed price depends on the survey and drawings.
Do I need a bat survey?
Very often. Barns are common bat roosts, and planning authorities usually ask for an ecology survey.
How long does a barn conversion take?
Typically 6 to 12 months on site, depending on the building’s condition.
Who approves a barn conversion in Sunbury-on-Thames?
Planning matters in Sunbury-on-Thames go to the council covering your address, and the work needs building control approval. We prepare and submit the applications for you.