Basement and cellar conversions in Sutton

Covering Sutton

We work in Sutton (CR44, SM1, SM2) and the places around it, including Carshalton, Banstead and Ewell.

Homes in London

London projects often mean working on period terraces with neighbours on both sides, tight access through the house and conservation area controls, so careful planning and party wall work matter as much as the build.

What is a basement conversion?

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
Ventilation, heating and electrics
Finished floors, walls and ceilings

What will a basement conversion cost?

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 Sutton?

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.

What can change the price or programme?

A pump for the drainage system needs a battery back-up.
Headroom of about 2.1 m or more is needed, which may mean lowering the floor.

What happens after I enquire?

Tell us about the project. Call, use the guide price tool or send the form with a few photos and a postcode.
We visit and measure. A surveyor checks the house, the boundaries and the ground, and discusses what is realistic.
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.

Basement and cellar conversions: common questions

How long does it take?

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

Will my neighbours be affected?

New basements usually need party wall agreements. We handle the notices and surveyors.

How do I get a price for basement and cellar conversions in Sutton?

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 Sutton

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