Covering Belfast
Alongside Belfast, we also cover Newtownabbey (4 miles to the north), Holywood and Lisburn.
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 is included in a double-storey extension in Belfast?
A double-storey extension adds new rooms on both the ground and first floor in one build, typically a larger kitchen or living space downstairs and an extra bedroom or bathroom above. Because the roof and foundations are shared, the cost per square metre is usually lower than a single-storey extension.
- Householder planning application
- Structural engineer’s design and calculations
- Foundations, steelwork, brick and block walls, roof
What is the guide price for a double-storey extension in Belfast?
Use these ranges to budget for double-storey extensions; the survey turns them into a fixed price for the agreed specification.
| Double-storey extensions | Guide price incl. VAT |
|---|---|
| Standard specification | £2,400 to £2,900 per m² |
| Good specification | £2,900 to £3,400 per m² |
| High specification | £3,400 to £3,850 per m² |
How is a double-storey extension approved in Belfast?
Projects in Northern Ireland need planning clearance from one of the eleven councils and building control approval, also from the council. The Party Wall etc. Act does not extend to Northern Ireland, so work near neighbours is agreed directly and documented carefully.
Two-storey extensions in Northern Ireland normally need planning permission from the council, plus building control approval.
What can affect a double-storey extension?
- Side extensions close to a boundary are often set back or stepped down so they do not create a terraced effect.
- The first-floor link can mean moving a bathroom or reshaping the landing.
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.
- Price and paperwork. The design is priced line by line, and we submit the planning and building control applications.
- We build it. Work follows an agreed programme, with inspections at each stage and a final sign-off.
Double-storey extensions: common questions
Is a two-storey extension better value than a single-storey one?
Per square metre, usually yes, because the foundations and roof serve two floors of space.
How long does a two-storey extension take?
Around 14 to 24 weeks on site, plus the planning period before that.
Do you work in Belfast?
Yes. Belfast is within our coverage for double-storey extensions, along with nearby Newtownabbey and Holywood.
Also covering
- Double-storey extensions in Newtownabbey
- Double-storey extensions in Holywood
- Double-storey extensions in Lisburn
- Double-storey extensions in Comber
Learn more about double-storey extensions, or see every project we cover in Belfast.