Basement and cellar conversions · Henley-on-Thames

Basement and cellar conversions in Henley-on-Thames

From the first site visit to the final building control sign-off, we manage basement and cellar conversions in Henley-on-Thames so you only have one company to deal with.

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 conversionsGuide 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?

  1. Send us the details. Give us a postcode, a rough idea of size and some photos, by phone, form or the guide price tool.
  2. Free site visit. We measure up, look at access, drains and the structure, and talk through options and budget.
  3. Drawings, approvals, written quote. We prepare the design, apply for the approvals it needs, and give you a fixed price in writing.
  4. 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

Learn more about basement and cellar conversions, or see every project we cover in Henley-on-Thames.

Planning an extension, loft or new home?

Get a guide price in two minutes, then book a free site visit.

CallGet a quote