Covering Banstead
Alongside Banstead, we also cover Sutton, Ewell (3 miles to the north-west) and Epsom.
Homes in the South East
The South East has a lot of 1930s and post-war semi-detached housing, well suited to rear extensions and hip-to-gable loft conversions, alongside period properties in conservation areas that need a more careful design.
What do you get with a basement conversion?
A basement conversion turns an existing cellar into dry, usable rooms, or excavates a new basement under a house. Converting an existing cellar is far simpler and cheaper than digging a new one, and often does not need planning permission.
- Damp and structural survey
- Ventilation, heating and electrics
- Finished floors, walls and ceilings
What will a basement conversion cost?
Typical ranges for basement and cellar conversions. Ground conditions, access and specification move the final figure, which we fix in writing before work starts.
| 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 Banstead?
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 should Banstead homeowners check first?
- Groundwater levels drive the waterproofing design and cost.
- A pump for the drainage system needs a battery back-up.
From first call to completion
- 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.
- Drawings, approvals, written quote. We prepare the design, apply for the approvals it needs, and give you a fixed price in writing.
- Construction and completion. One site lead co-ordinates every trade through to the building control certificate.
Basement and cellar conversions: common questions
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.
Will my neighbours be affected?
New basements usually need party wall agreements. We handle the notices and surveyors.
Do you work in Banstead?
Yes. Banstead is within our coverage for basement and cellar conversions, along with nearby Sutton and Ewell.
Basement and cellar conversions near Banstead
- Basement and cellar conversions in Sutton
- Basement and cellar conversions in Ewell
- Basement and cellar conversions in Epsom
- Basement and cellar conversions in Coulsdon
Learn more about basement and cellar conversions, or see every project we cover in Banstead.

