Basement and cellar conversions in Poole

Covering Poole

Poole is about 20 miles east of Dorchester. We also cover Bournemouth (5 miles to the east), Wimborne Minster and Swanage.

Homes in the South West

In the South West, matching local stone, render or slate is often the main design question, and conservation areas and listed buildings are common in historic towns.

What is included in a basement conversion in Poole?

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.

Waterproofing design and installation
Underpinning or lowering the floor where needed
Ventilation, heating and electrics

How much should I budget for a basement conversion?

Indicative costs for basement and cellar conversions. London and the South East usually sit towards the top of each range.

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

What approvals does a basement conversion need in England?

In England we deal with the council’s planning team for permission or a lawful development certificate, with building control (the council or a registered building control approver) for inspections, and with neighbours under the Party Wall etc. Act 1996 where it applies.

Converting an existing cellar with no external changes usually does not need planning permission in England. Digging a new basement or adding a lightwell often does, and many councils have basement policies.

What should I think about before starting?

New basements nearly always involve the Party Wall Act in England and Wales.
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.

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.

How do I get a price for basement and cellar conversions in Poole?

Use the guide price tool for a ballpark figure, then book a visit for a fixed written price for the agreed specification.

Basement and cellar conversions near Poole

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