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 County Londonderry?
In County Londonderry, a barn conversion typically costs £1,550–£2,600 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 £232,500–£390,000. Prices across Northern Ireland are typically 14% below the UK average for this kind of work, which is reflected in the range for County Londonderry. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| Smaller project (105 m²) | £163,000–£273,000 |
| Typical project (150 m²) | £232,500–£390,000 |
| Larger project (210 m²) | £325,500–£546,000 |
| Rate per m² | £1,550–£2,600 |
Your quote will depend mainly on:
- Glazing and finishes
- Services and drainage
- Condition of the existing structure
- Insulation approach
A guide range is only a starting point: the guide price tool gives an instant figure for your size, and a free survey turns it into a fixed quote.
Do you need planning permission for a barn conversion in County Londonderry?
Before anything is built in County Londonderry, we confirm which approvals apply in Northern Ireland. In Northern Ireland a barn conversion needs planning permission; planning policy supports reusing suitable rural buildings.
In Northern Ireland building control approval comes from the council, usually through a full plans application or a building notice, with inspections during the work and a completion certificate at the end.
We check this for your address before design work starts, so there are no surprises later.
What we handle
On a typical barn conversion we handle:
- Structural survey and feasibility
- Ecology and bat survey coordination
- Building control completion
- New roof covering where needed
- Planning or prior approval application
- Insulation that respects the existing fabric
How long does it take?
Allow 6 to 12 months on site depending on condition. Allow time beforehand for drawings and approvals, usually 4 to 9 months.
Building in County Londonderry
Across Northern Ireland, bungalows and chalet bungalows are common, so loft conversions and rear extensions are popular projects.
Towns we cover in County Londonderry include Derry, Coleraine, Limavady and Magherafelt.
How it works
- 01
Visit and measured survey
A free visit to understand the project, check access and take measurements.
- 02
Design and pricing
Design options, then a fixed quote based on the chosen drawings and specification.
- 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 County Londonderry
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 County Londonderry?
In County Londonderry, a barn conversion typically costs £1,550–£2,600 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 £232,500–£390,000. 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.
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.
Who approves a barn conversion in County Londonderry?
Planning matters in County Londonderry go to the council covering your address, and the work needs building control approval. We prepare and submit the applications for you.
Do I need planning permission for a barn conversion in County Londonderry?
In Northern Ireland a barn conversion needs planning permission; planning policy supports reusing suitable rural buildings.
