Double-storey extensions in Ballymoney

Covering Ballymoney

Our coverage around Ballymoney (BT53) also includes Coleraine, Portrush and Ballymena.

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 Ballymoney?

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.

Measured survey, design and planning drawings
Householder planning application
Windows, insulation, plastering, electrics and plumbing

How much does a double-storey extension cost in Ballymoney?

Guide prices for double-storey extensions, including VAT where it applies. Your fixed price is confirmed in writing after the survey.

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

Planning and building rules in Ballymoney

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.

Two-storey extensions in Northern Ireland normally need planning permission from the council, plus building control approval.

What can affect a double-storey extension?

Neighbours’ light is assessed using the 45-degree guide many councils use.
The new roof is tied into the old one, so roof tiles and ridge details need to match.

What are the steps?

Tell us about the project. Call, use the guide price tool or send the form with a few photos and a postcode.
We visit and measure. A surveyor checks the house, the boundaries and the ground, and discusses what is realistic.
Drawings, approvals, written quote. We prepare the design, apply for the approvals it needs, and give you a fixed price in writing.
Build and hand over. Our teams build to the programme, building control inspects, and you get the completion paperwork at the end.

Double-storey extensions: common questions

How much does a two-storey extension cost?

Typically about £2,400 to £3,850 per square metre of new floor area including VAT. A 40 m² extension across two floors is often around £100,000 to £150,000 depending on specification.

How long does a two-storey extension take?

Around 14 to 24 weeks on site, plus the planning period before that.

How do I get a price for double-storey extensions in Ballymoney?

Use the guide price tool for a ballpark figure, then book a visit for a fixed written price for the agreed specification.

Also covering

Learn more about double-storey extensions, or see every project we cover in Ballymoney.