Covering County Londonderry
We cover County Londonderry, including Derry, Coleraine, Limavady and Magherafelt.
Homes in County Londonderry
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 goes into 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.
- Damp and structural survey
- Waterproofing design and installation
- Ventilation, heating and electrics
How much should I budget for a basement conversion?
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 should I think about before starting?
- Groundwater levels drive the waterproofing design and cost.
- Headroom of about 2.1 m or more is needed, which may mean lowering the floor.
How does the project run?
- 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.
- Construction and completion. One site lead co-ordinates every trade through to the building control certificate.
What people ask before starting
Does a cellar conversion need planning permission?
Usually not if nothing changes outside. New basements and lightwells often do.
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.
Who deals with the council for a project in County Londonderry?
We do. We prepare the drawings, submit planning or permitted development paperwork if needed, and arrange building control inspections.
Other towns nearby
- Basement and cellar conversions in Derry
- Basement and cellar conversions in Coleraine
- Basement and cellar conversions in Limavady
- Basement and cellar conversions in Magherafelt
Learn more about basement and cellar conversions, or see every project we cover in County Londonderry.