Single-storey rear extensions across Bangor, County Down
If you live in Bangor, County Down and want more space without moving, a single-storey extension is one of the most practical ways to get it. We handle the drawings, approvals and the build.
- Guide price in Bangor, County DownFrom £18,000 inc VAT
- PlanningNI permitted development (rear 3–4 m) or planning
- Build time10–16 weeks on site
- Postcode districtsBT19, BT20
Single-storey extension prices in Bangor, County Down
Prices below are for Bangor, County Down, using the Northern Ireland factor of ×0.86. They are guide ranges including VAT for the build only, not a quote.
Typical rates in Bangor, County Down: £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.
Do I need planning permission in Bangor, County Down?
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.
Homes in conservation areas, areas of townscape character and listed buildings have tighter rules, so we always check the property's status and planning history before design starts.
Building close to a public sewer needs the agreement of NI Water, which we check during design.
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.
Applications are decided by your council, which handles local planning in Northern Ireland.
Extensions in and around Bangor, County Down
Site visits are available across Bangor, County Down (BT19, BT20). Nearby, we also take on projects in Newtownards (5 miles), Downpatrick (23 miles), Banbridge (33 miles), Newry (43 miles).
For homes towards County Antrim, Carrickfergus is around 7 miles away. In Northern Ireland, extension projects follow the NI planning rules and council building control, which we account for from the first survey.
When a single-storey extension makes sense
- Homeowners who want open-plan living onto the garden
- Terraced houses that want a deeper kitchen across the full width
- Semi-detached and detached houses with a usable rear garden
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
A designer visits, takes measurements and photos, and discusses layouts, budget and timing with you.
Design and approvals
Drawings are prepared and agreed with you, then submitted for the right planning route and building regulations approval.
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
Our team builds the extension, keeps you updated weekly and finishes with building control sign-off.
Single-storey extension questions answered
Who do I contract with for a single-storey extension in Bangor, County Down?
Your contract is with S&K Property Investments and Improvement Ltd, which designs and manages the project and the build teams who carry it out.
How long does a single-storey extension take to build in Bangor, County Down?
On site, typically 10 to 16 weeks once approvals are in place. Before that, allow 4–12 weeks design and approvals.
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Bangor, County Down, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.
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.
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.
Book a free site visit in Bangor, County Down
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.