Covering Henley-on-Thames
Henley-on-Thames is about 21 miles south-east of Oxford. We also cover Reading (6 miles to the south-west), Maidenhead and Wokingham.
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.
- Waterproofing design and installation
- Lightwells and windows for daylight and escape
- Finished floors, walls and ceilings
What will a basement conversion cost?
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 |
What approvals does a basement conversion need in England?
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 Henley-on-Thames homeowners check first?
- Groundwater levels drive the waterproofing design and cost.
- New basements nearly always involve the Party Wall Act in England and Wales.
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.
- Free site visit. We measure up, look at access, drains and the structure, and talk through options and budget.
- 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.
How long does it take?
About 6 to 12 weeks for a cellar conversion and 16 to 30 weeks for a new basement.
Who deals with the council for a project in Henley-on-Thames?
We do. We prepare the drawings, submit planning or permitted development paperwork if needed, and arrange building control inspections.
Also covering
- Basement and cellar conversions in Reading
- Basement and cellar conversions in Maidenhead
- Basement and cellar conversions in Wokingham
- Basement and cellar conversions in High Wycombe
Learn more about basement and cellar conversions, or see every project we cover in Henley-on-Thames.

