Covering Ballymoney
Ballymoney sits 40 miles north-west of Belfast, with Coleraine 8 miles to the north-west and Portrush 10 miles to the north-west.
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 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
- Underpinning or lowering the floor where needed
- Lightwells and windows for daylight and escape
How much should I budget for a basement conversion?
Typical ranges for basement and cellar conversions. Ground conditions, access and specification move the final figure, which we fix in writing before work starts.
| 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 |
How is a basement conversion approved 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.
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.
- Headroom of about 2.1 m or more is needed, which may mean lowering the floor.
What happens after I enquire?
- Send us the details. Give us a postcode, a rough idea of size and some photos, by phone, form or the guide price tool.
- We visit and measure. A surveyor checks the house, the boundaries and the ground, and discusses what is realistic.
- 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.
Basement and cellar conversions: common questions
How do you keep a basement dry?
With a designed waterproofing system, usually a cavity drain membrane draining to a pump, sometimes combined with tanking.
How long does it take?
About 6 to 12 weeks for a cellar conversion and 16 to 30 weeks for a new basement.
Can you visit a house in Ballymoney 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.
Basement and cellar conversions in nearby towns
- Basement and cellar conversions in Coleraine
- Basement and cellar conversions in Portrush
- Basement and cellar conversions in Ballymena
- Basement and cellar conversions in Limavady
Learn more about basement and cellar conversions, or see every project we cover in Ballymoney.

