Covering Holywood
We work in Holywood (BT18) and the places around it, including Newtownabbey, Belfast and Carrickfergus.
Homes in County Down
Northern Ireland has a high proportion of detached houses and bungalows outside the cities, which often suit side extensions, rear extensions and upward extensions.
What is included in a single-storey extension in Holywood?
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.
- Building control application and inspections
- Foundations, drainage and structural steel
- Brickwork, roof, glazing and insulation
What will a single-storey extension cost?
What single-storey extensions typically cost. These are guide ranges; the written quote for your house replaces them.
| 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.
What should I think about before starting?
- Large glazed areas need to meet energy rules, which can shape the size of doors and rooflights.
- Kitchens and doors have long lead times, so we order them early.
What are the steps?
- Send us the details. Give us a postcode, a rough idea of size and some photos, by phone, form or the guide price tool.
- 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 Holywood
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 need to dig up the drains?
Sometimes. If a public sewer runs under the extension, the water company has to agree a build-over or a diversion. We check this at survey stage.
Can you visit a house in Holywood to quote?
Yes. After a short call we arrange a site visit to measure up and agree what the design needs to do, then send a written price.
Single-storey extensions in nearby towns
- Single-storey extensions in Newtownabbey
- Single-storey extensions in Belfast
- Single-storey extensions in Carrickfergus
- Single-storey extensions in Newtownards
Learn more about single-storey extensions, or see every project we cover in Holywood.

