Antrim over-garage extensions, designed and built
Planning an over-garage extension in Antrim? We survey the house, work out the planning route, draw the design and build it, so you deal with one team from the first visit to the completion certificate.
- Guide price in AntrimFrom £20,500 inc VAT
- PlanningPermission from the council needed
- Build time12–18 weeks on site
- Postcode districtsBT41
Local to Antrim
Site visits are available across Antrim (BT41). The same team covers Ballymena (10 miles), Newtownabbey (13 miles), Belfast (14 miles), Lisburn (15 miles), all within easy reach.
In Northern Ireland, extension projects follow the NI planning rules and council building control, which we account for from the first survey.
Included in a typical project
- Design and householder planning application
- Opening into the existing first floor
- New floor structure, walls and roof
- Strengthening or rebuilding the garage walls if needed
- Structural survey of garage walls and foundations
Will the council need to approve it?
In Northern Ireland the Planning (General Permitted Development) Order 2015 lets some single-storey rear extensions go ahead without planning permission, up to 3 m on a semi-detached or terraced house and 4 m on a detached house, within height and boundary limits. Larger, side and two-storey extensions normally need planning permission from the council, and building control approval is separate.
The planning position for a specific Antrim address depends on its history and any designations, which is why we check it at the first visit.
Northern Ireland has no Party Wall Act. Where work is on or close to a shared boundary, we agree access and protection with your neighbour in writing before work starts.
Building close to a public sewer needs the agreement of NI Water, which we check during design.
Applications are decided by your council, which handles local planning in Northern Ireland.
Guide prices for Antrim
For Antrim we adjust our national guide rates by ×0.86, the factor we use for Northern Ireland. Figures include VAT; your written quote after the survey replaces them.
Typical rates in Antrim: £1,550 to £2,920 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| Over a single garage 12 m² | £20,500 – £25,500 | £21,500 – £28,000 | £27,500 – £35,500 |
| Over a large single garage 16 m² | £24,500 – £30,500 | £28,500 – £37,500 | £37,000 – £47,000 |
| Over a double garage 24 m² | £37,000 – £45,500 | £43,000 – £56,000 | £55,500 – £70,500 |
For a figure based on your own dimensions, use our guide-price tool.
From first visit to completion
Site visits are free and there is no obligation. Where drawings are needed, the design stage is priced in writing before it starts.
Free site visit
It starts with a visit to your house to measure, check access and talk through ideas and budget.
Design and approvals
Once the layout is agreed, we deal with the council: planning permission or written confirmation that none is needed, plus building control.
Fixed written price
The price is fixed in writing once the design is settled, with a clear programme and payment stages.
Build and sign-off
We build it with one project manager, book the building control inspections and hand over the completion certificate.
Your questions about an over-garage extension in Antrim
Will my neighbours in Antrim be involved?
If a planning application is needed, the council notifies neighbours. Where work is close to a shared boundary, we agree access and protection with them in writing.
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Antrim, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.
How long does an over-garage extension take to build in Antrim?
On site, typically 12 to 18 weeks once approvals are in place. Before that, allow 8–14 weeks design and approvals.
How much does a room over a garage cost?
Our guide range is about £1,550 to £2,920 per m² including VAT. A single-garage room of about 12 m² usually costs £21,500 to £28,000 at standard spec, more if the garage needs rebuilding.
Can I keep using the garage during the build?
Usually not for parking. The garage roof is removed and the space below is used for access and props for part of the build.
Book a free site visit in Antrim
We will measure up, check the planning position and give you honest guide figures.
- Free, no-obligation site visit
- Planning route checked before you spend on drawings
- Written price once the design is agreed
- Building control sign-off at the end
Prefer to talk? Call 0800 088 6341 or .
Book a free site visit
Tell us a little about the project and we will arrange a time.