Basement and cellar conversions · Tonbridge

Basement and cellar conversions in Tonbridge

We take on basement and cellar conversions in Tonbridge as a complete project: survey, drawings, planning or permitted development checks, building control and the construction itself.

Covering Tonbridge

Tonbridge sits 12 miles south-west of Maidstone, with Tunbridge Wells 4 miles to the south and Sevenoaks 6 miles to the north-west.

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 is included in a basement conversion in Tonbridge?

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
  • Underpinning or lowering the floor where needed
  • Lightwells and windows for daylight and escape

What is the guide price for a basement conversion in Tonbridge?

What basement and cellar conversions typically cost. These are guide ranges; the written quote for your house replaces them.

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

How is a basement conversion approved in Tonbridge?

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. Digging a new basement or adding a lightwell often does, and many councils have basement policies.

What should Tonbridge homeowners check first?

  • 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.

From first call to completion

  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. Price and paperwork. The design is priced line by line, and we submit the planning and building control applications.
  4. Construction and completion. One site lead co-ordinates every trade through to the building control certificate.

Your questions answered

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 long does it take?

About 6 to 12 weeks for a cellar conversion and 16 to 30 weeks for a new basement.

Can you visit a house in Tonbridge to quote?

Yes. After a short call we arrange a site visit to measure up and agree what the design needs to do, then send a written price.

Also covering

Learn more about basement and cellar conversions, or see every project we cover in Tonbridge.

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