Side return extensions in County Antrim
We design and build side return extensions for houses in County Antrim, with a written price once the survey and design are done and one point of contact throughout.
- Guide priceFrom £15,000 inc VAT
- PlanningDepends on the NI limits; checked at the survey
- Towns covered8
- Site visitFree, no obligation
Towns in County Antrim
Included in a typical project
- Glazed, sloping or flat roof with rooflights
- Survey of the outrigger, boundary wall and drainage
- Design to keep daylight in the middle of the house
- Kitchen-ready shell or full finish
- Removal of the side wall and new steelwork
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.
How much does a side return extension cost in County 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 County 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 |
Try the guide-price tool to see a range for your own size and finish.
Do I need planning permission in County Antrim?
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.
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.
Covering County Antrim
Towns we cover in County Antrim include Belfast, Lisburn, Newtownabbey, Castlereagh, Carrickfergus, Ballymena, Antrim, Larne. 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.
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
We visit your County Antrim home, measure up, talk through what you want and check the planning position.
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 Antrim
Do you cover all of County Antrim?
Yes, across the whole of County Antrim. Site visits are free and there is no obligation.
Will my neighbours in County 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 County 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 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 County Antrim, more in London.
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 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.