What is a basement conversion?
A basement conversion turns an existing cellar into living space, or excavates a new basement under the house or garden. Waterproofing, structural support and daylight are the main design challenges.
How much does a basement conversion cost in Dungannon?
In Dungannon, a basement conversion typically costs £1,650–£2,750 per m² for converting an existing cellar, including VAT at 20% (standard rate). For a typical 30 m² project that is roughly £49,500–£82,500. The guide for Dungannon reflects typical costs in Northern Ireland, roughly 14% below the UK-wide figure. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| Smaller project (21 m²) | £34,500–£58,000 |
| Typical project (30 m²) | £49,500–£82,500 |
| Larger project (42 m²) | £69,500–£115,500 |
| Rate per m² | £1,650–£2,750 |
The biggest cost drivers are:
- Waterproofing system
- Existing cellar or new excavation
- Agreements with neighbours on shared walls
- Ground water and access
Use the guide price tool to see how size and specification change the figure, then ask for a written, itemised quote.
Do you need planning permission for a basement conversion in Dungannon?
Whether you need planning permission depends on your house and its location in Northern Ireland. In Northern Ireland converting an existing cellar usually does not need planning permission; new excavation and external changes may.
In Northern Ireland building control approval comes from the council, usually through a full plans application or a building notice, with inspections during the work and a completion certificate at the end.
If the answer is not clear-cut, we can apply for formal confirmation before you commit to the build.
What we handle
On a typical basement conversion we handle:
- Waterproofing design (tanking or cavity drain membrane)
- Lightwells and windows
- Insulation, ventilation and drainage pumps
- Structural and ground survey
- Underpinning or new structure where needed
- Electrics, heating and plastering
How long does it take?
Expect 8 to 16 weeks for a cellar conversion; longer for new excavation. Design and approvals come first and typically take 3 to 5 months, depending on the approval route.
Building in Dungannon
Northern Ireland has many detached and semi-detached homes on generous plots, which suits single-storey rear extensions and garage conversions.
Projects in Dungannon (BT70 and BT71) are surveyed in person before we quote, so the price reflects your actual property.
How it works
- 01
Survey and brief
We visit, discuss your ideas and budget, and survey the property or site at no cost.
- 02
Design and fixed quote
Drawings, structural calculations and an itemised, fixed price for the agreed specification.
- 03
Permissions sorted
Applications, building control and neighbour arrangements, all before the start date.
- 04
Build and handover
Work follows the agreed programme, with inspections along the way and a completion certificate at the end.
Questions about basement conversions in Dungannon
Can a basement be a bedroom?
Yes, with a suitable escape route such as a lightwell window or protected stair.
Do you build basement conversions in Dungannon?
Yes. We build basement conversions across Dungannon, including postcodes BT70 and BT71. Every project starts with a free home visit.
Do I need planning permission for a basement conversion in Dungannon?
In Northern Ireland converting an existing cellar usually does not need planning permission; new excavation and external changes may.
Is new excavation worth it?
It can be in high-value areas, but costs are high. We give a feasibility view before design starts.
How much does a basement conversion cost in Dungannon?
In Dungannon, a basement conversion typically costs £1,650–£2,750 per m² for converting an existing cellar, including VAT at 20% (standard rate). A typical 30 m² project comes to roughly £49,500–£82,500. Your fixed price depends on the survey and drawings.
How long does it take?
A cellar conversion takes around 8 to 16 weeks; new basements take longer.