Extensions over a garage in Coleraine
If you live in Coleraine and need more room without moving, an extension over a garage is worth a serious look. We handle the drawings, approvals, structure and build.
Quick reference for homeowners in Coleraine.
- Postcode districts
- BT51 and BT52
- County / area
- County Londonderry, Northern Ireland
- Price region
- Northern Ireland
- Guide price
- £27,500–£40,500 (£1,540–£2,240 per m²)
- Approval route
- Planning permission is needed: permitted development side extensions in Northern Ireland can't be more than 4 m high, which rules out two storeys.
- Nearest towns
- Portstewart (3.8 miles), Portrush (4.4 miles), Ballymoney (7.5 miles)
- Distance to Derry
- about 27.1 miles
- First visit
- Free, no obligation
About an extension over a garage
An extension over a garage is a new first-floor room built on top of an existing attached garage, usually a bedroom, en-suite or study. It uses a footprint you already have, so it adds floor space without taking any garden. The garage walls and foundations often need strengthening or replacing to carry the new floor.
We cover Coleraine (BT51 and BT52) and the places around it, including Portstewart (3.8 miles), Portrush (4.4 miles) and Ballymoney.
What it costs in Coleraine
Our guide for Northern Ireland is £1,540–£2,240 per m² including VAT. On a project with 3 m × 6 m of new first-floor space (18 m²), that puts an extension over a garage in Coleraine at roughly £27,500–£40,500. The fastest way to a firmer number is a free site visit, after which we price the design stage in writing.
| Spec | Per m² | 3 m × 6 m of new first-floor space (18 m²) |
|---|---|---|
| Essential | £1,420–£2,060 per m² | £25,500–£37,000 |
| Standard | £1,540–£2,240 per m² | £27,500–£40,500 |
| Premium | £1,850–£2,690 per m² | £33,500–£48,500 |
Planning and building control in Coleraine
In Northern Ireland, permitted development for two-storey work is set out for rear extensions, so building over a side garage normally needs a planning application, which costs £347 per dwelling. Councils aim for an average of 15 weeks for local applications. Building control approval is also needed, including fire separation if the garage stays in use.
Approval in Northern Ireland: Planning application for works to a house: £347. Councils aim to decide local applications within an average of 15 weeks; many take longer.
Building control: Building control approval from the local council under the Building Regulations (Northern Ireland), using the Technical Booklets.
Design points for Coleraine homes
Checking the garage foundations
Garages are often built on shallow strip footings sized for a single-storey wall and a light roof. A trial hole shows their depth and condition, and the engineer decides whether they can carry two storeys or need underpinning or new foundations inside the garage.
Matching the house
A room over a garage usually sits beside the front of the house in full view, so roof form, ridge height, windows and brick matter. Setting the front wall and ridge back slightly from the main house usually helps it look as if it belongs.
How we'd run your project
Measure and listen
A visit to Coleraine to understand how you live in the house now and what the extra rooms need to do, plus a first look at the structure.
Drawings and permission
Our designers produce plans and elevations, then we take care of planning or permitted development checks with the council covering Coleraine.
Detail and price
Construction drawings, engineer's calculations and building control sign-off, then a written fixed price for the build.
On site
One project lead runs the job, keeps you updated and arranges inspections at each stage until completion.
Questions about extensions over a garage in Coleraine
Who handles building control for a project in Coleraine?
We handle it as part of the project. What's needed in Northern Ireland: building control approval from the local council under the Building Regulations (Northern Ireland), using the Technical Booklets. We prepare the drawings and the engineer's calculations, book the inspections and pass you the completion paperwork at the end.
How much does an extension over a garage cost in Coleraine?
Our guide for Northern Ireland, which covers Coleraine, is £1,540–£2,240 per m² including VAT. A typical project with 3 m × 6 m of new first-floor space (18 m²) comes to about £27,500–£40,500. Design and approval fees are extra, and we fix the build price in writing once the design is agreed.
Do I need planning permission for an extension over a garage in Coleraine?
Coleraine is in Northern Ireland. Planning permission is needed: permitted development side extensions in Northern Ireland can't be more than 4 m high, which rules out two storeys.
Do I need to convert the garage as well?
No. You can keep the garage for parking or storage and build only the room above, as long as the floor between them and any door into the house meet fire separation rules. Converting the garage at the same time is often good value, because the walls and foundations may be upgraded anyway.
How do I get into a room over the garage?
Usually through a new opening off the existing landing or a bedroom, so the stairs stay where they are. If the floor levels do not match, a step or two may be needed inside the new room. Where a landing opening is not practical, a new stair from a converted garage is an option.
Nearby
Other towns near Coleraine:
Other extensions in Coleraine
- Rear
- Side
- Wraparound
- Part two-storey
- First floor
- Semi-detached
- Detached
- Kitchen and bedrooms
- Bedroom and en-suite
All two-storey extension services in Coleraine · Extensions over a garage across County Londonderry
Book a free site visit in Coleraine and we'll tell you what's possible, what approvals you need and what the design stage would cost.