Coleraine, County Londonderry
Semi-detached rear extension in Coleraine
Single or two-storey extensions for semi-detached houses, with side access and one party wall. If you live in Coleraine and want to know what a semi-detached rear extension would cost and whether it needs planning, start with the online guide price or a free site visit.
We cover Coleraine (BT52) as part of our County Londonderry work. In Coleraine we measure the attached neighbour's extension at the survey, because it often sets the sensible depth for yours.
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 Coleraine?
Guide prices for a semi-detached rear extension in Coleraine start from our Northern Ireland rate of £1,650–£2,700 per square metre, including VAT. 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 |
We put a fixed price in writing once the design is agreed, and explain any provisional sums such as foundations.
Do you need planning permission for a semi-detached rear extension in Coleraine?
Here is how the rules in Northern Ireland apply to a semi-detached rear extension in Coleraine.
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. Before any drawing we look up the property's history with the council, because earlier extensions and removed rights change the answer.
What are homes in Coleraine like to extend?
Semis and detached houses are typical of Coleraine, and many have room for a rear extension within Northern Ireland's permitted development limits.
How a semi-detached rear extension in Coleraine 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.
Drawings and budget
Floor plans and elevations for the options, each with a guide price.
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.
Fixed price and build
A written price for the agreed design, a start date and a named contact through the build, ending with the building control completion certificate.
Semi-detached rear extensions near Coleraine
Neighbouring places we cover include Portstewart (3.8 miles) and Limavady (12.6 miles).
- Semi-detached rear extension in Portstewart
- Semi-detached rear extension in Limavady
- Semi-detached rear extension in Ballymena
- Semi-detached rear extension in Magherafelt
- Semi-detached rear extension in Derry~Londonderry
Other work in Coleraine:
FAQ
Semi-detached rear extension questions in Coleraine
Will I need a structural engineer?
Yes for the beam over the new opening and usually the foundations; we arrange them and their calculations go to building control.
Do you handle building control in Coleraine?
Yes. We apply to the council's building control team and hand over the completion certificate.
Single or two-storey on a semi?
Two-storey if you need bedrooms, single-storey if you need a bigger kitchen. Planning risk is lower for single-storey.
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.
Is the site visit in Coleraine free?
Yes. We visit, measure up and talk through the options with no cost and no obligation.
Do I need a party wall agreement?
Northern Ireland has no Party Wall Act; we agree any shared-wall work with your neighbour in writing.