Side return extensions in County Down
County Down homeowners can use us for the whole side return extension project: survey, design, planning or permitted development checks, building regulations and the build itself.
- Guide priceFrom £15,000 inc VAT
- PlanningDepends on the NI limits; checked at the survey
- Towns covered5
- Site visitFree, no obligation

Towns in County Down
Who a side return extension suits
- Narrow galley kitchens
- Victorian and Edwardian terraces with a rear outrigger
- Homes where the garden is too small to lose much depth
Light is the design problem. A side return can make the middle of the house darker if the roof is solid, so we model the daylight and usually recommend a glazed slope or a run of rooflights along the boundary edge.
Local to County Down
Towns we cover in County Down include Bangor, County Down, Newtownards, Newry, Banbridge, Downpatrick. Northern Ireland's housing ranges from city terraces to large numbers of detached houses and bungalows on rural plots, many in render, where single-storey extensions fit easily.
Side return extension prices in County Down
These guide figures apply our Northern Ireland adjustment (×0.86) to national rates. They include VAT at 20% and cover the build itself; design and council fees are listed separately.
Typical rates in County Down: £1,810 to £3,270 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 1.8 m × 4.5 m 8 m² | £15,000 – £18,500 | £16,500 – £21,000 | £20,500 – £26,500 |
| 2 m × 5.5 m 11 m² | £19,500 – £24,000 | £22,500 – £28,500 | £28,000 – £36,000 |
| 2.2 m × 7 m 15 m² | £27,000 – £32,500 | £30,500 – £39,000 | £38,500 – £49,500 |
Want a range for your exact size? The guide-price tool takes about a minute.
Do I need planning permission in 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.
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.
Building close to a public sewer needs the agreement of NI Water, which we check during design.
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.
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
A designer visits, takes measurements and photos, and discusses layouts, budget and timing with you.
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
Our team builds the extension, keeps you updated weekly and finishes with building control sign-off.
Common questions in County Down
Do I need building regulations approval in County Down?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
Do you cover all of County Down?
Yes, across the whole of County Down. Site visits are free and there is no obligation.
Who do I contract with for a side return extension in 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.
Can I combine a side return with a rear extension?
Yes. That combination is a wraparound extension, which adds the most space to a terraced house.
Will the kitchen be darker?
Not if the roof is designed well. A glazed roof or a line of rooflights along the boundary usually makes the room brighter than before.
Book a free site visit in 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.