Basement and cellar conversions in Richmond

Covering Richmond

Our coverage around Richmond (TW9) also includes Isleworth (2 miles to the north-west) and Hounslow.

Homes in London

Terraced houses dominate many London neighbourhoods, so most projects involve shared walls, narrow access and a party wall process. Conservation areas are widespread, and some boroughs have their own mansard and basement guidance.

What is included in a basement conversion in Richmond?

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
Ventilation, heating and electrics

How much does a basement conversion cost in Richmond?

Use these ranges to budget for basement and cellar conversions; the survey turns them into a fixed price for the agreed specification.

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 Richmond?

English projects need planning clearance from the local council, building regulations sign-off from building control, and party wall notices where the work is on or near a shared boundary. We prepare and manage all three.

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

What can change the price or programme?

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

How does the project run?

Start with a conversation. A short call or the online form is enough for us to understand what you want to build.
Free site visit. We measure up, look at access, drains and the structure, and talk through options and budget.
Price and paperwork. The design is priced line by line, and we submit the planning and building control applications.
Build and hand over. Our teams build to the programme, building control inspects, and you get the completion paperwork at the end.

What people ask before starting

Does a cellar conversion need planning permission?

Usually not if nothing changes outside. New basements and lightwells often do.

How long does it take?

About 6 to 12 weeks for a cellar conversion and 16 to 30 weeks for a new basement.

Do you work in Richmond?

Yes. Richmond is within our coverage for basement and cellar conversions, along with nearby Isleworth and Hounslow.

Basement and cellar conversions near Richmond

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