Covering Derry
Our coverage around Derry (BT47) also includes Strabane, Limavady and Coleraine.
Homes in County Londonderry
Across Northern Ireland you find city terraces, suburban semis and rural bungalows and farmhouses, so the right approach depends on the plot and the planning history.
What does a basement conversion involve?
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
- Damp and structural survey
- Ventilation, heating and electrics
What is the guide price for a basement conversion in Derry?
Guide prices for basement and cellar conversions, including VAT where it applies. Your fixed price is confirmed in writing after the survey.
| 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 |
What approvals does a basement conversion need in Northern Ireland?
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 change the price or programme?
- 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.
- Build and hand over. Our teams build to the programme, building control inspects, and you get the completion paperwork at the end.
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.
Who deals with the council for a project in Derry?
We do. We prepare the drawings, submit planning or permitted development paperwork if needed, and arrange building control inspections.
Basement and cellar conversions near Derry
- Basement and cellar conversions in Strabane
- Basement and cellar conversions in Limavady
- Basement and cellar conversions in Coleraine
- Basement and cellar conversions in Omagh
Learn more about basement and cellar conversions, or see every project we cover in Derry.