Covering Beaconsfield
We work in Beaconsfield (HP9) and the places around it, including Amersham, High Wycombe and Maidenhead.
Homes in the South East
Many South East homes are inter-war or post-war semis and detached houses with room for rear and side extensions, while historic town centres and villages bring conservation area and listed building controls.
What does a basement conversion involve?
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
- Waterproofing design and installation
- Lightwells and windows for daylight and escape
How much does a basement conversion cost in Beaconsfield?
What basement and cellar conversions typically cost. These are guide ranges; the written quote for your house replaces them.
| 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 Beaconsfield?
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.
What can affect a basement conversion?
- 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 are the steps?
- Tell us about the project. Call, use the guide price tool or send the form with a few photos and a postcode.
- 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.
- Construction and completion. One site lead co-ordinates every trade through to the building control certificate.
Questions about a basement conversion in Beaconsfield
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 do you keep a basement dry?
With a designed waterproofing system, usually a cavity drain membrane draining to a pump, sometimes combined with tanking.
How do I get a price for basement and cellar conversions in Beaconsfield?
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 Beaconsfield
- Basement and cellar conversions in Amersham
- Basement and cellar conversions in High Wycombe
- Basement and cellar conversions in Maidenhead
- Basement and cellar conversions in Slough
Learn more about basement and cellar conversions, or see every project we cover in Beaconsfield.

