Basement and cellar conversions in Haverfordwest

Covering Haverfordwest

Haverfordwest is about 29 miles west of Carmarthen. We also cover Pembroke Dock (8 miles to the south), Tenby and Cardigan.

Homes in Dyfed

Welsh homes include long terraces built into hillsides, stone cottages and modern estates, and sloping sites often shape how and where an extension can go.

What is included in a basement conversion in Haverfordwest?

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
Lightwells and windows for daylight and escape
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 Haverfordwest

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 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?

Start with a conversation. A short call or the online form is enough for us to understand what you want to build.
Survey at your house. We look at the existing structure, services and access, and agree what the design needs to achieve.
Design and fixed price. You get drawings and a written price for the agreed specification before anything is ordered.
We build it. Work follows an agreed programme, with inspections at each stage and a final sign-off.

Your questions answered

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.

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 Haverfordwest 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.

Other towns nearby

Learn more about basement and cellar conversions, or see every project we cover in Haverfordwest.