Basement and cellar conversions in Gloucester

Covering Gloucester

Alongside Gloucester, we also cover Cheltenham (7 miles to the east), Stroud and Ledbury.

Homes in the South West

Homes in the South West range from coastal and rural properties in stone and slate to city terraces and modern estates, so extensions are designed to match the local materials.

What does a basement conversion involve?

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.

Damp and structural survey
Ventilation, heating and electrics
Finished floors, walls and ceilings

How much does a basement conversion cost in Gloucester?

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

How is a basement conversion approved in Gloucester?

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 can affect a basement conversion?

Groundwater levels drive the waterproofing design and cost.
Headroom of about 2.1 m or more is needed, which may mean lowering the floor.

From first call to completion

Send us the details. Give us a postcode, a rough idea of size and some photos, by phone, form or the guide price tool.
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.

What people ask before starting

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.

Will my neighbours be affected?

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

Who deals with the council for a project in Gloucester?

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 Gloucester.