Basement and cellar conversions · Worthing

Basement and cellar conversions in Worthing

Planning basement and cellar conversions in Worthing? We design and build them for houses across West Sussex, and we fix the price for the agreed specification in writing before any building work starts.

Covering Worthing

Worthing is about 22 miles south of Crawley. We also cover Littlehampton (7 miles to the west), Hove and Brighton.

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 goes into a basement conversion?

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.

  • Waterproofing design and installation
  • Underpinning or lowering the floor where needed
  • Ventilation, heating and electrics

How much should I budget for a basement conversion?

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

How is a basement conversion approved in Worthing?

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 change the price or programme?

  • Groundwater levels drive the waterproofing design and cost.
  • A pump for the drainage system needs a battery back-up.

What happens after I enquire?

  1. Start with a conversation. A short call or the online form is enough for us to understand what you want to build.
  2. We visit and measure. A surveyor checks the house, the boundaries and the ground, and discusses what is realistic.
  3. Price and paperwork. The design is priced line by line, and we submit the planning and building control applications.
  4. Build and hand over. Our teams build to the programme, building control inspects, and you get the completion paperwork at the end.

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.

How long does it take?

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

Do you work in Worthing?

Yes. Worthing is within our coverage for basement and cellar conversions, along with nearby Littlehampton and Hove.

Other towns nearby

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

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