Basement and cellar conversions in Shirley

Covering Shirley

Our coverage around Shirley (B90) also includes Solihull, Acocks Green and Birmingham.

Homes in the West Midlands

Red-brick terraces and inter-war semis make up much of the housing in the West Midlands, which suits rear extensions, dormer lofts and hip-to-gable conversions, with more modern estates on the edges of the towns.

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
Lightwells and windows for daylight and escape
Finished floors, walls and ceilings

How much should I budget for a basement conversion?

Use these ranges to budget for basement and cellar conversions; the survey turns them into a fixed price for the agreed specification.

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 Shirley?

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?

New basements nearly always involve the Party Wall Act in England and Wales.
A pump for the drainage system needs a battery back-up.

What happens after I enquire?

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.
Build and hand over. Our teams build to the programme, building control inspects, and you get the completion paperwork at the end.

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.

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 Shirley?

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 Shirley.