Side return extensions across Antrim
A side return extension in Antrim starts with the right design and the right approval route. We take care of both, then build it with our own project management.
- Guide price in AntrimFrom £15,000 inc VAT
- PlanningDepends on the NI limits; checked at the survey
- Build time10–14 weeks on site
- Postcode districtsBT41
Who a side return extension suits
- Victorian and Edwardian terraces with a rear outrigger
- Homes where the garden is too small to lose much depth
- Narrow galley kitchens
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.
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.
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.
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.
Guide prices for Antrim
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 Antrim: £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 |
For a figure based on your own dimensions, use our guide-price tool.
Local to Antrim
We cover Antrim and the postcode districts BT41. Neighbouring towns we cover include Ballymena (10 miles), Newtownabbey (13 miles), Belfast (14 miles), Lisburn (15 miles).
Just over the County Londonderry border, Magherafelt is about 17 miles away. In Northern Ireland, extension projects follow the NI planning rules and council building control, which we account for from the first survey.
Our process, step by step
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
We confirm the build price in writing, based on the approved drawings and the finishes you have chosen.
Build and sign-off
Work is carried out to the agreed programme, inspected by building control and signed off at the end.
Your questions about a side return extension in Antrim
How long does a side return extension take to build in Antrim?
On site, typically 10 to 14 weeks once approvals are in place. Before that, allow 6–12 weeks design and approvals.
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.
Who do I contract with for a side return extension in Antrim?
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.
How much does a side return extension cost?
Our guide range is about £1,810 to £3,270 per m² including VAT, so a typical 2 m × 5.5 m infill lands around £22,500 to £28,500 at standard spec in Antrim, more in London.
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.