Covering Lisburn
Lisburn is about 7 miles south-west of Belfast. We also cover Belfast (7 miles to the north-east), Newtownabbey and Holywood.
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 is included in a basement conversion in Lisburn?
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.
- Waterproofing design and installation
- Underpinning or lowering the floor where needed
- Lightwells and windows for daylight and escape
What will a basement conversion cost?
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 Lisburn?
Northern Ireland projects need planning clearance and building control approval from the local council. We prepare the applications and agree any work near neighbouring property directly with the neighbours.
In Northern Ireland new basements and external changes normally need planning permission; building control approval is needed.
What can affect a basement conversion?
- A pump for the drainage system needs a battery back-up.
- Headroom of about 2.1 m or more is needed, which may mean lowering the floor.
What happens after I enquire?
- 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.
- 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.
Your questions answered
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.
How do I get a price for basement and cellar conversions in Lisburn?
Use the guide price tool for a ballpark figure, then book a visit for a fixed written price for the agreed specification.
Basement and cellar conversions near Lisburn
- Basement and cellar conversions in Belfast
- Basement and cellar conversions in Newtownabbey
- Basement and cellar conversions in Holywood
- Basement and cellar conversions in Comber
Learn more about basement and cellar conversions, or see every project we cover in Lisburn.