Covering Epsom
Epsom sits 15 miles north-east of Guildford, with Ewell 2 miles to the north-east and Banstead 3 miles to the east.
Homes in the South East
Housing across the South East mixes inter-war semis, post-war estates and older cottages in villages and market towns, so rear and side extensions, hip-to-gable lofts and garage conversions all come up regularly.
What is included in a basement conversion in Epsom?
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.
- Underpinning or lowering the floor where needed
- Lightwells and windows for daylight and escape
- Ventilation, heating and electrics
What is the guide price for a basement conversion in Epsom?
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 |
How is a basement conversion approved in Epsom?
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 can affect a basement conversion?
- New basements nearly always involve the Party Wall Act in England and Wales.
- A pump for the drainage system needs a battery back-up.
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.
- 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.
What people ask before starting
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.
Will my neighbours be affected?
New basements usually need party wall agreements. We handle the notices and surveyors.
How do I get a price for basement and cellar conversions in Epsom?
Use the guide price tool for a ballpark figure, then book a visit for a fixed written price for the agreed specification.
Also covering
- Basement and cellar conversions in Ewell
- Basement and cellar conversions in Banstead
- Basement and cellar conversions in Sutton
- Basement and cellar conversions in Leatherhead
Learn more about basement and cellar conversions, or see every project we cover in Epsom.

