Carrickfergus, County Antrim
Two-storey rear extension in Carrickfergus
We plan and build two-storey rear extensions for homeowners in Carrickfergus. A larger kitchen downstairs and an extra bedroom or bathroom upstairs, under one roof. Start with a free site visit, then a written price once the design is agreed.
We cover Carrickfergus (BT38) as part of our County Antrim work. In Carrickfergus, a two-storey rear extension is worth comparing with the cost of moving once stamp duty, agents' and legal fees are counted.
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 two-storey rear extension cost in Carrickfergus?
For Carrickfergus we work from the Northern Ireland rate: £1,570–£2,350 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 × 5 m footprint, two floors (30 m²) | £47,000–£70,500 |
| 4 m × 6 m footprint, two floors (48 m²) | £75,000–£113,000 |
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 two-storey rear extension in Carrickfergus?
The planning route for a two-storey rear extension in Carrickfergus is set by Northern Ireland's householder rules and your 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.
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 Carrickfergus like to extend?
Semis and detached houses are typical of Carrickfergus, and many have room for a rear extension within Northern Ireland's permitted development limits.
How a two-storey rear extension in Carrickfergus 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.
Two-storey rear extensions near Carrickfergus
We also build two-storey rear extensions in nearby Holywood (5.4 miles) and Newtownabbey (5.6 miles).
- Two-storey rear extension in Holywood
- Two-storey rear extension in Newtownabbey
- Two-storey rear extension in Bangor
- Two-storey rear extension in Dundonald
- Two-storey rear extension in Larne
Other work in Carrickfergus:
FAQ
Two-storey rear extension questions in Carrickfergus
How long does a rear extension take to build in Carrickfergus?
Most single-storey rear extensions take 10 to 16 weeks on site and two-storey extensions 16 to 26 weeks, after design and approvals.
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.
What is the 45-degree rule?
Many councils check that a two-storey extension does not cross a 45-degree line drawn from the nearest habitable window of the neighbouring house. We test it at the first drawing.
Do you handle building control in Carrickfergus?
Yes. We apply to the council's building control team and hand over the completion certificate.
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.
How much does a two-storey rear extension cost in Carrickfergus?
As a guide, £1,570–£2,350 per square metre including VAT for a standard specification. For example, 3 m × 5 m footprint, two floors (30 m²): about £47,000–£70,500 at that rate. Your written price follows the survey.