Covering West Glamorgan
Our coverage across West Glamorgan includes Swansea, Neath, Ystalyfera and Pontarddulais.
Homes in West Glamorgan
Across Wales you find valley terraces, coastal towns, rural stone houses and newer estates, so access, slopes and local materials all feature in the design.
What goes into a basement conversion?
Everything below ground depends on keeping water out. We design the waterproofing system (usually a cavity drain membrane with a pump, or tanking) to the relevant British Standard guidance, then add insulation, ventilation, light and an escape route. New basements involve underpinning and a party wall process and are designed with a structural engineer.
- Damp and structural survey
- Waterproofing design and installation
- Underpinning or lowering the floor where needed
How much should I budget for a basement conversion?
What basement and cellar conversions typically cost. These are guide ranges; the written quote for your house replaces them.
| 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 |
Do you need permission for a basement conversion in West Glamorgan?
Planning decisions in Wales are made by the local council, using permitted development rules set by the Welsh Government rather than England’s. Building regulations in Wales have their own approved documents, and the Party Wall etc. Act 1996 applies to work on shared walls and boundaries.
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.
- A pump for the drainage system needs a battery back-up.
From first call to completion
- Tell us about the project. Call, use the guide price tool or send the form with a few photos and a postcode.
- Survey at your house. We look at the existing structure, services and access, and agree what the design needs to achieve.
- Price and paperwork. The design is priced line by line, and we submit the planning and building control applications.
- Construction and completion. One site lead co-ordinates every trade through to the building control certificate.
Your questions answered
How much does a basement conversion cost?
Converting an existing cellar costs about £1,900 to £3,000 per square metre including VAT. A new excavated basement is around £4,200 to £6,600 per square metre.
How long does it take?
About 6 to 12 weeks for a cellar conversion and 16 to 30 weeks for a new basement.
Can you visit a house in West Glamorgan 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.
Basement and cellar conversions in nearby towns
- Basement and cellar conversions in Swansea
- Basement and cellar conversions in Neath
- Basement and cellar conversions in Ystalyfera
- Basement and cellar conversions in Pontarddulais
Learn more about basement and cellar conversions, or see every project we cover in West Glamorgan.