Larne, County Antrim
Semi-detached rear extension in Larne
Semi-detached rear extension in Larne: single or two-storey extensions for semi-detached houses, with side access and one party wall. We measure the house, show you what the rules allow, price it in writing and build it.
Larne sits in County Antrim, with postcode districts including BT40. Where a Larne semi already has a small lean-to at the back, we usually replace it rather than extend it.
Book a free site visit
Tell us about the house and we'll call to arrange a free, no-obligation visit.
How much does a semi-detached rear extension cost in Larne?
For Larne we work from the Northern Ireland rate: £1,650–£2,700 per square metre of new floor, including VAT, standard specification. Northern Ireland prices are the lowest in our range.
| Size | Guide price inc VAT |
|---|---|
| 3 m wide × 4 m deep (12 m²) | £20,000–£32,500 |
| 4 m wide × 5 m deep (20 m²) | £33,000–£54,000 |
| 4 m wide × 6 m deep (24 m²) | £39,500–£64,500 |
Your written price follows a measured survey and an agreed design, so it reflects your house, not an average.
Do you need planning permission for a semi-detached rear extension in Larne?
Here is how the rules in Northern Ireland apply to a semi-detached rear extension in Larne.
Northern Ireland's permitted development rules allow a single-storey rear extension of 3 metres on terraced and semi-detached houses and 4 metres on detached houses, with a 4 metre height limit. Listed buildings, conservation areas and houses with removed rights need planning permission from the council.
Northern Ireland's 2015 Order allows a two-storey rear extension of up to 3 metres where at least 7 metres is left to the rear boundary. Anything larger, or in a conservation area, needs a planning application to the council.
Northern Ireland has no larger-extension prior approval route; anything beyond permitted development needs a planning application.
Conservation areas, Areas of Outstanding Natural Beauty and listed buildings restrict permitted development in Northern Ireland. We check your house's planning history and any conservation area before drawing, so the route is clear before you spend on plans.
What are homes in Larne like to extend?
Semis and detached houses are typical of Larne, and many have room for a rear extension within Northern Ireland's permitted development limits.
How a semi-detached rear extension in Larne comes together
Survey visit
We visit free of charge, measure up, check access, drainage and neighbours' extensions, and note what you want the room to do.
Options and costs
We draw layout options and price each one, so the budget shapes the design rather than surprising you later.
Planning and regulations
We take the design through the right planning route, then produce the construction drawings and engineer's calculations for council building control.
Written price, then build
Once the design and approvals are in place, you get a fixed written price and programme, and we build through to sign-off.
Semi-detached rear extensions near Larne
We also build rear extensions for semi-detached houses in nearby Carrickfergus (9.3 miles) and Newtownabbey (13.6 miles).
- Semi-detached rear extension in Carrickfergus
- Semi-detached rear extension in Newtownabbey
- Semi-detached rear extension in Bangor
- Semi-detached rear extension in Holywood
- Semi-detached rear extension in Dundonald
Other work in Larne:
FAQ
Semi-detached rear extension questions in Larne
Can I live at home while the extension is built?
Usually yes. Most of the work is outside until the back wall is opened near the end, and that stage is screened off.
Do I need planning permission for a rear extension in Larne?
Often not for a single-storey rear extension of up to 3 metres (4 metres detached) under Northern Ireland's permitted development rules, outside conservation areas.
What if my neighbour has already extended?
That can make a matching depth easier to justify. We measure theirs at the survey.
Who will build my extension?
Vetted building teams working under contract to us. Your contract is with S&K Property Investments and Improvement Ltd for the design and the build.
Can you match the brick or stone on my Larne house?
We source the closest match and show you samples before ordering; reclaimed materials are often the best match on older houses.
How much does a semi-detached rear extension cost in Larne?
As a guide, £1,650–£2,700 per square metre including VAT for a standard specification. For example, 3 m wide × 4 m deep (12 m²): about £20,000–£32,500 at that rate. Your written price follows the survey.