Covering Carrickfergus
Alongside Carrickfergus, we also cover Holywood, Newtownabbey (6 miles to the south-west) and Bangor.
Homes in County Antrim
Housing in Northern Ireland mixes terraces in Belfast and Derry with detached houses and bungalows in towns and rural areas, many with room to extend.
What do you get with a single-storey extension?
We design the extension around how you use the house: where the light comes from, how the new room joins the old one, and what happens to the drains and the garden. The structure is built in brick or block to match the house, finished with a flat roof and lantern or a pitched roof, then insulated, plastered and handed back ready to decorate.
- Measured survey and design drawings
- Building control application and inspections
- Brickwork, roof, glazing and insulation
What will a single-storey extension cost?
Use these ranges to budget for single-storey extensions; the survey turns them into a fixed price for the agreed specification.
| Single-storey extensions | Guide price incl. VAT |
|---|---|
| Standard specification | £2,600 to £3,000 per m² |
| Good specification | £3,000 to £3,500 per m² |
| High specification | £3,500 to £4,000 per m² |
What approvals does a single-storey extension need in Northern Ireland?
In Northern Ireland the council handles both planning and building control. Permitted development rules are set by the Planning (General Permitted Development) Order (Northern Ireland) 2015, and there is no party wall act, so we agree access and protection with neighbours in writing.
In Northern Ireland permitted development is set by the Planning (General Permitted Development) Order (Northern Ireland) 2015, and small single-storey rear extensions can often go ahead without an application. Building control approval from the council is still needed.
What should I think about before starting?
- Drains under the footprint may need diverting or a build-over agreement with the water company.
- Kitchens and doors have long lead times, so we order them early.
How does the project run?
- Tell us about the project. Call, use the guide price tool or send the form with a few photos and a postcode.
- Free site visit. We measure up, look at access, drains and the structure, and talk through options and budget.
- Design and fixed price. You get drawings and a written price for the agreed specification before anything is ordered.
- We build it. Work follows an agreed programme, with inspections at each stage and a final sign-off.
Questions about a single-storey extension in Carrickfergus
How much does a single-storey extension cost?
Most single-storey extensions cost about £2,600 to £4,000 per square metre including VAT, depending on specification, glazing and ground conditions. We give a fixed price in writing for the agreed specification after the survey.
Can we stay in the house during the build?
Usually yes. We keep the existing house closed off from the works until the knock-through near the end, and agree a temporary kitchen set-up with you if the kitchen is affected.
Do you work in Carrickfergus?
Yes. Carrickfergus is within our coverage for single-storey extensions, along with nearby Holywood and Newtownabbey.
Single-storey extensions near Carrickfergus
- Single-storey extensions in Holywood
- Single-storey extensions in Newtownabbey
- Single-storey extensions in Bangor
- Single-storey extensions in Belfast
Learn more about single-storey extensions, or see every project we cover in Carrickfergus.

