Coleraine single-storey extensions, designed and built
Planning a single-storey extension in Coleraine? 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 ColeraineFrom £18,000 inc VAT
- PlanningNI permitted development (rear 3–4 m) or planning
- Build time10–16 weeks on site
- Postcode districtsBT52
Working in Coleraine
Across BT52, we can visit, measure and advise. Nearby, we also take on projects in Limavady (13 miles), Magherafelt (26 miles), Derry/Londonderry (27 miles).
In Northern Ireland, extension projects follow the NI planning rules and council building control, which we account for from the first survey.
What should I budget for a single-storey extension in Coleraine?
Labour and material costs vary across the UK, so for Coleraine we use our Northern Ireland factor (×0.86). The ranges include VAT and exclude design, structural and council fees.
Typical rates in Coleraine: £1,500 to £2,920 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 3 m × 4 m 12 m² | £18,000 – £21,500 | £21,000 – £27,000 | £26,500 – £35,500 |
| 4 m × 5 m 20 m² | £30,000 – £35,500 | £35,000 – £45,000 | £44,500 – £58,500 |
| 5 m × 6 m 30 m² | £45,000 – £53,000 | £52,500 – £67,500 | £67,000 – £88,000 |
For a figure based on your own dimensions, use our guide-price tool.
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.
In a conservation area or area of townscape character the permitted development rights are more limited, listed homes need listed building consent, and if rights have been removed by a condition, any extension needs an application.
In Northern Ireland building control is run by the councils under the Building Regulations (Northern Ireland). We submit full plans or a building notice and book the inspections through to completion.
Applications are decided by your council, which handles local planning in Northern Ireland.
What is included
- Measured survey and design
- Doors, windows, insulation, plastering and first fix to finish
- Flat or pitched roof, rooflights or lantern
- Walls, steel beams and the new opening into the house
How the project works
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
First, a site visit: we look at the house, garden, access and drains and listen to what you need.
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
With the design and specification agreed, you get a fixed written price and a start date.
Build and sign-off
The build is managed from start to finish, inspected at each stage and signed off on completion.
Single-storey extension questions answered
Will my neighbours in Coleraine 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.
Do you cover all of Coleraine?
Yes. We cover Coleraine and the surrounding parts of County Londonderry. Site visits are free and there is no obligation.
Do I need building regulations approval in Coleraine?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
Will I need a steel beam?
Almost always. Opening up the rear wall to join the new room to the house needs a beam, usually steel, sized by a structural engineer. It is included in our quotes.
Can I stay in the house during the build?
Usually yes. Most of the work happens outside until the final weeks, when we open the rear wall. We plan that stage carefully and seal the opening with a temporary screen to keep dust down.
Book a free site visit in Coleraine
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.