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 Trowbridge?
In Trowbridge, 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. Prices in the South West sit near the national average for this kind of work, and the range for Trowbridge reflects that. 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 |
Your quote will depend mainly on:
- Glazing and finishes
- Condition of the existing structure
- Services and drainage
- Access to the site
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 Trowbridge?
Before anything is built in Trowbridge, we confirm which approvals apply 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
On a typical barn conversion we handle:
- Insulation that respects the existing fabric
- Ecology and bat survey coordination
- Building control completion
- Structural repairs and new floor slab
- Services, drainage and septic or treatment plant
- Structural survey and feasibility
How long does it take?
The build itself usually takes 6 to 12 months on site depending on condition. Allow time beforehand for drawings and approvals, usually 4 to 9 months.
Building in Trowbridge
The South West mixes stone and render cottages with post-war and newer estates, and local materials matter more here when matching an extension.
If your home is in Trowbridge or close by in Melksham, Bath and Frome, 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
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 barn conversions in Trowbridge
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.
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 Trowbridge?
In Trowbridge, 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.
Do you build barn conversions in Trowbridge?
Yes. We build barn conversions across Trowbridge, including postcodes BA14. Every project starts with a free home visit.
How long does a barn conversion take?
Typically 6 to 12 months on site, depending on the building’s condition.
