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 Hertfordshire?
In Hertfordshire, a barn conversion typically costs £1,900–£3,200 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 £285,000–£480,000. The guide for Hertfordshire reflects typical costs in the East of England, roughly 6% above the UK-wide figure. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| Smaller project (105 m²) | £199,500–£336,000 |
| Typical project (150 m²) | £285,000–£480,000 |
| Larger project (210 m²) | £399,000–£672,000 |
| Rate per m² | £1,900–£3,200 |
Your quote will depend mainly on:
- Condition of the existing structure
- Access to the site
- Glazing and finishes
- Planning conditions and ecology
For a figure based on your own measurements, try the guide price tool, then book a free home visit for a fixed quote.
Do you need planning permission for a barn conversion in Hertfordshire?
The approval route for Hertfordshire is set by planning law 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.
If the answer is not clear-cut, we can apply for formal confirmation before you commit to the build.
What we handle
On a typical barn conversion we handle:
- Ecology and bat survey coordination
- Building control completion
- New roof covering where needed
- Structural repairs and new floor slab
- Services, drainage and septic or treatment plant
- Planning or prior approval application
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 Hertfordshire
Across the East of England, 1930s and post-war semis, newer estates and rural cottages all feature, each with different extension and loft options.
Towns we cover in Hertfordshire include Watford, Hemel Hempstead, Stevenage, St Albans, Welwyn Garden City and Cheshunt.
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
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 Hertfordshire
How long does a barn conversion take?
Typically 6 to 12 months on site, depending on the building’s condition.
How much does a barn conversion cost in Hertfordshire?
In Hertfordshire, a barn conversion typically costs £1,900–£3,200 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 £285,000–£480,000. 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.
Who approves a barn conversion in Hertfordshire?
Planning matters in Hertfordshire go to the council covering your address, and the work needs building control approval. We prepare and submit the applications for you.