Basement and cellar conversions in Bournemouth

Covering Bournemouth

Our coverage around Bournemouth (BH1, BH2, BH7) also includes Christchurch, Poole and Wimborne Minster.

Homes in the South West

Homes in the South West range from coastal and rural properties in stone and slate to city terraces and modern estates, so extensions are designed to match the local materials.

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
Underpinning or lowering the floor where needed
Lightwells and windows for daylight and escape

How much should I budget for a basement conversion?

Guide prices for basement and cellar conversions, including VAT where it applies. Your fixed price is confirmed in writing after the survey.

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 Bournemouth?

Projects in England go through two separate checks. Planning (or confirmation that the work is permitted development) comes from the district, borough or unitary council, and building regulations approval comes from the council’s building control team or a registered building control approver. Where work touches a shared wall or digs near a neighbour’s foundations, the Party Wall etc. Act 1996 applies.

Converting an existing cellar with no external changes usually does not need planning permission in England.

What should Bournemouth homeowners check first?

Groundwater levels drive the waterproofing design and cost.
A pump for the drainage system needs a battery back-up.

What are the steps?

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.
Price and paperwork. The design is priced line by line, and we submit the planning and building control applications.
We build it. Work follows an agreed programme, with inspections at each stage and a final sign-off.

Basement and cellar conversions: common questions

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.

Do you work in Bournemouth?

Yes. Bournemouth is within our coverage for basement and cellar conversions, along with nearby Christchurch and Poole.

Other towns nearby

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