What is a basement conversion?
A basement conversion turns an existing cellar into living space, or excavates a new basement under the house or garden. Waterproofing, structural support and daylight are the main design challenges.
How much does a basement conversion cost in Crewe?
In Crewe, a basement conversion typically costs £1,800–£3,000 per m² for converting an existing cellar, including VAT at 20% (standard rate). For a typical 30 m² project that is roughly £54,000–£90,000. That range is adjusted for the North West, where domestic building work typically costs around 6% below the national average. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| Smaller project (21 m²) | £38,000–£63,000 |
| Typical project (30 m²) | £54,000–£90,000 |
| Larger project (42 m²) | £75,500–£126,000 |
| Rate per m² | £1,800–£3,000 |
Your quote will depend mainly on:
- Existing cellar or new excavation
- Party wall surveyor fees
- Lightwells
- Floor lowering and underpinning
Your exact price depends on the survey and drawings. The guide price tool gives a quick range in the meantime.
Do you need planning permission for a basement conversion in Crewe?
Before anything is built in Crewe, we confirm which approvals apply in England. In England converting an existing cellar with no external change usually does not need planning permission. New excavation, lightwells and changes to the front often do, and some councils, particularly in London, have specific basement policies.
Building regulations approval comes from the council’s building control service or a registered building control approver. The work is inspected at key stages, such as foundations, drainage and insulation, and a completion certificate is issued at the end.
At the survey we check your house’s planning history and any restrictions, and tell you which route applies.
What we handle
What we take care of:
- Insulation, ventilation and drainage pumps
- Lightwells and windows
- Electrics, heating and plastering
- Party wall notices
- Structural and ground survey
- Building control sign-off
How long does it take?
Expect 8 to 16 weeks for a cellar conversion; longer for new excavation. Before that, surveys, drawings and approvals usually take 3 to 5 months, longer if the council asks for changes.
Building in Crewe
Terraced streets across the North West often suit rear dormers and single-storey kitchen extensions.
Our Crewe coverage includes postcode districts CW1 and CW98, and we also work in nearby places such as Winsford, Kidsgrove and Congleton.
How it works
- 01
Survey and brief
We visit, discuss your ideas and budget, and survey the property or site at no cost.
- 02
Design and fixed quote
Drawings, structural calculations and an itemised, fixed price for the agreed specification.
- 03
Permissions sorted
Applications, building control and neighbour arrangements, all before the start date.
- 04
Build and sign-off
We run the build to a written programme and hand over the completion certificate.
Questions about basement conversions in Crewe
How long does it take?
A cellar conversion takes around 8 to 16 weeks; new basements take longer.
Is new excavation worth it?
It can be in high-value areas, but costs are high. We give a feasibility view before design starts.
Do I need party wall agreements?
In England and Wales, excavating near a neighbour’s foundations usually triggers the Party Wall etc. Act 1996.
How much does a basement conversion cost in Crewe?
In Crewe, a basement conversion typically costs £1,800–£3,000 per m² for converting an existing cellar, including VAT at 20% (standard rate). A typical 30 m² project comes to roughly £54,000–£90,000. Your fixed price depends on the survey and drawings.
Who approves a basement conversion in Crewe?
Planning matters in Crewe go to the council covering your address, and the work needs building control approval. We prepare and submit the applications for you.