Basement and cellar conversions in County Antrim

Covering County Antrim

Our coverage across County Antrim includes Belfast, Lisburn, Newtownabbey and Carrickfergus.

Homes in County Antrim

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 do you get with a basement conversion?

A basement conversion turns an existing cellar into dry, usable rooms, or excavates a new basement under a house. Converting an existing cellar is far simpler and cheaper than digging a new one, and often does not need planning permission.

Planning and building control applications to the council
Lightwells and windows for daylight and escape
Ventilation, heating and electrics

What is the guide price for a basement conversion in County Antrim?

What basement and cellar conversions typically cost. These are guide ranges; the written quote for your house replaces them.

Basement and cellar conversions	Guide price incl. VAT
Existing cellar conversion	£1,900 to £3,000 per m²
New basement excavation	£4,200 to £6,600 per m²

Do you need permission for a basement conversion in County Antrim?

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.

In Northern Ireland new basements and external changes normally need planning permission; building control approval is needed.

What can change the price or programme?

Groundwater levels drive the waterproofing design and cost.
A pump for the drainage system needs a battery back-up.

From first call to completion

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.
Drawings, approvals, written quote. We prepare the design, apply for the approvals it needs, and give you a fixed price in writing.
We build it. Work follows an agreed programme, with inspections at each stage and a final sign-off.

What people ask before starting

How much does a basement conversion cost?

Converting an existing cellar costs about £1,900 to £3,000 per square metre including VAT. A new excavated basement is around £4,200 to £6,600 per square metre.

Does a cellar conversion need planning permission?

Usually not if nothing changes outside. New basements and lightwells often do.

Do you work in County Antrim?

Yes. County Antrim is within our coverage for basement and cellar conversions, along with nearby Belfast and Lisburn.

Also covering

Learn more about basement and cellar conversions, or see every project we cover in County Antrim.