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 Dorset?
In Dorset, a barn conversion typically costs £1,850–£3,050 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 £277,500–£457,500. Building costs in the South West are close to the UK average, so the figures for Dorset are close to our national guide. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| Smaller project (105 m²) | £194,000–£320,000 |
| Typical project (150 m²) | £277,500–£457,500 |
| Larger project (210 m²) | £388,500–£640,500 |
| Rate per m² | £1,850–£3,050 |
The main things that change the cost:
- Access to the site
- Insulation approach
- Planning conditions and ecology
- Condition of the existing structure
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 Dorset?
Approvals for a barn conversion in Dorset follow the rules for 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:
- Planning or prior approval application
- Ecology and bat survey coordination
- Services, drainage and septic or treatment plant
- New roof covering where needed
- Structural survey and feasibility
- Building control completion
How long does it take?
Allow 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 Dorset
In parts of the South West, protected landscapes and conservation areas shape what can be built, so materials and roof forms are chosen carefully.
Towns we cover in Dorset include Bournemouth, Poole, Weymouth and Christchurch.
How it works
- 01
Survey and brief
We visit, discuss your ideas and budget, and survey the property or site at no cost.
- 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
Build and sign-off
We run the build to a written programme and hand over the completion certificate.
Questions about barn conversions in Dorset
How long does a barn conversion take in Dorset?
Typically 6 to 12 months on site depending on condition. Design and approvals beforehand usually take 4 to 9 months.
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.
How much does a barn conversion cost in Dorset?
In Dorset, a barn conversion typically costs £1,850–£3,050 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 £277,500–£457,500. Your fixed price depends on the survey and drawings.
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.
Do I need a bat survey?
Very often. Barns are common bat roosts, and planning authorities usually ask for an ecology survey.