What is a garage conversion?
A garage conversion turns an integral or attached garage into habitable space, such as a study, playroom, bedroom or utility. The garage door is replaced with a wall and window, the floor is raised and insulated, and the walls and roof are brought up to building regulations.
How much does a garage conversion cost in County Londonderry?
In County Londonderry, a garage conversion typically costs £15,500–£26,000 for a single integral garage, including VAT at 20% (standard rate). The guide for County Londonderry reflects typical costs in Northern Ireland, roughly 14% below the UK-wide figure. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| A single integral garage | £15,500–£26,000 |
| Higher specification | £26,000–£32,500 |
The biggest cost drivers are:
- Whether planning permission is needed
- Foundations under the old door opening
- Heating and flooring
- Single or double garage
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 garage conversion in County Londonderry?
The approval route for County Londonderry is set by planning law in Northern Ireland. In Northern Ireland a garage conversion usually does not need planning permission if permitted development rights apply, but building control approval is needed.
Northern Ireland has no Party Wall Act. Work on shared walls relies on agreement with the neighbour and common law, so we agree the arrangements in writing before work starts.
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 garage conversion:
- Building control completion
- Floor raised with insulation and damp-proof membrane
- New wall and window to replace the garage door
- Foundation check under the garage door opening
- Wall and ceiling insulation
- Electrics, heating and plastering
How long does it take?
The build itself usually takes 3 to 6 weeks on site. Before that, surveys, drawings and approvals usually take 6 to 12 weeks, longer if the council asks for changes.
Building in County Londonderry
Northern Ireland has many detached and semi-detached homes on generous plots, which suits single-storey rear extensions and garage conversions.
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
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 garage conversions in County Londonderry
How long does a garage conversion take in County Londonderry?
Typically 3 to 6 weeks on site. Design and approvals beforehand usually take 6 to 12 weeks.
How much does a garage conversion cost in County Londonderry?
In County Londonderry, a garage conversion typically costs £15,500–£26,000 for a single integral garage, including VAT at 20% (standard rate). Your fixed price depends on the survey and drawings.
Can a detached garage be converted?
Yes, but using it as separate living accommodation may need planning permission.
Do I need planning permission for a garage conversion in County Londonderry?
In Northern Ireland a garage conversion usually does not need planning permission if permitted development rights apply, but building control approval is needed.
Can the floor be level with the house?
Yes. The garage floor is raised and insulated to match the house floor level.
Do I need building regulations approval?
Yes. Converting a garage to a habitable room needs building control approval for insulation, ventilation, fire safety and the new wall.