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 Staines?
In Staines, 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. 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 (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 |
The biggest cost drivers are:
- Condition of the existing structure
- Services and drainage
- Access to the site
- Glazing and finishes
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 barn conversion in Staines?
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.
At the survey we check your house’s planning history and any restrictions, and tell you which route applies.
What we handle
Handled as part of most barn conversions:
- Services, drainage and septic or treatment plant
- Insulation that respects the existing fabric
- Planning or prior approval application
- Building control completion
- Structural repairs and new floor slab
- New roof covering where needed
How long does it take?
The build itself usually takes 6 to 12 months on site depending on condition. Design and approvals come first and typically take 4 to 9 months, depending on the approval route.
Building in Staines
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.
From TW18 outwards, we take on projects throughout Staines and the surrounding parts of Surrey.
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
Construction and completion
We build, put right any snags and hand over the building control certificate.
Questions about barn conversions in Staines
Do I need planning permission for a barn conversion?
Yes. A barn conversion needs planning permission or, in England only, prior approval under the agricultural permitted development rules where the building qualifies. Listed barns also need listed building consent.
Can I get a mortgage for a barn conversion?
Specialist self-build and conversion mortgages release money in stages. We can provide the staged costings lenders ask for.
How long does a barn conversion take in Staines?
Typically 6 to 12 months on site depending on condition. Design and approvals beforehand usually take 4 to 9 months.
How much does a barn conversion cost in Staines?
In Staines, 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.
