Covering Deeside
Our coverage around Deeside (CH5) also includes Hawarden, Buckley and Flint.
Homes in Clwyd
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 is 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
- Underpinning or lowering the floor where needed
- Finished floors, walls and ceilings
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 |
Planning and building rules in Deeside
Welsh projects need planning clearance from the council under Welsh rules, building regulations approval under the Welsh approved documents, and party wall notices where the work affects a neighbour’s wall or foundations.
In Wales an existing cellar conversion usually does not need planning permission; new excavation and lightwells may.
What can affect a basement conversion?
- Groundwater levels drive the waterproofing design and cost.
- Headroom of about 2.1 m or more is needed, which may mean lowering the floor.
What happens after I enquire?
- Send us the details. Give us a postcode, a rough idea of size and some photos, by phone, form or the guide price tool.
- Free site visit. We measure up, look at access, drains and the structure, and talk through options and budget.
- Design and fixed price. You get drawings and a written price for the agreed specification before anything is ordered.
- Build and hand over. Our teams build to the programme, building control inspects, and you get the completion paperwork at the end.
Questions about a basement conversion in Deeside
How long does it take?
About 6 to 12 weeks for a cellar conversion and 16 to 30 weeks for a new basement.
Will my neighbours be affected?
New basements usually need party wall agreements. We handle the notices and surveyors.
Can you visit a house in Deeside 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 Hawarden
- Basement and cellar conversions in Buckley
- Basement and cellar conversions in Flint
- Basement and cellar conversions in Chester
Learn more about basement and cellar conversions, or see every project we cover in Deeside.

