Covering Tonypandy
Alongside Tonypandy, we also cover Rhondda, Pontypridd (5 miles to the east) and Aberdare.
Homes in Mid Glamorgan
Housing in Wales ranges from terraced streets in the valleys and older industrial towns to stone-built homes in rural areas and modern estates around the cities.
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.
- Underpinning or lowering the floor where needed
- Lightwells and windows for daylight and escape
- Ventilation, heating and electrics
What is the guide price for a basement conversion in Tonypandy?
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 Tonypandy?
In Wales the planning rules, including what counts as permitted development, are set by the Welsh Government, and Welsh building regulations differ in places from England’s. We check both against your house before drawings are finalised, and handle party wall notices where needed.
In Wales an existing cellar conversion usually does not need planning permission; new excavation and lightwells may.
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?
- Send us the details. Give us a postcode, a rough idea of size and some photos, by phone, form or the guide price tool.
- Survey at your house. We look at the existing structure, services and access, and agree what the design needs to achieve.
- Drawings, approvals, written quote. We prepare the design, apply for the approvals it needs, and give you a fixed price in writing.
- Build and hand over. Our teams build to the programme, building control inspects, and you get the completion paperwork at the end.
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.
Can you visit a house in Tonypandy 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.
Also covering
- Basement and cellar conversions in Rhondda
- Basement and cellar conversions in Pontypridd
- Basement and cellar conversions in Aberdare
- Basement and cellar conversions in Maesteg
Learn more about basement and cellar conversions, or see every project we cover in Tonypandy.

