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 Luton?
In Luton, a basement conversion typically costs £2,000–£3,400 per m² for converting an existing cellar, including VAT at 20% (standard rate). For a typical 30 m² project that is roughly £60,000–£102,000. Prices across the East of England are typically 6% above the UK average for this kind of work, which is reflected in the range for Luton. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| Smaller project (21 m²) | £42,000–£71,500 |
| Typical project (30 m²) | £60,000–£102,000 |
| Larger project (42 m²) | £84,000–£143,000 |
| Rate per m² | £2,000–£3,400 |
Your quote will depend mainly on:
- Ground water and access
- Party wall surveyor fees
- Existing cellar or new excavation
- Waterproofing system
For a figure based on your own measurements, try the guide price tool, then book a free home visit for a fixed quote.
Do you need planning permission for a basement conversion in Luton?
Whether you need planning permission depends on your house and its location 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.
Where work involves a shared wall, building on the boundary, or digging foundations within 3 metres of a neighbour’s building and deeper than its foundations (or within 6 metres for deeper work), the Party Wall etc. Act 1996 applies and notices must be served before work starts.
If the answer is not clear-cut, we can apply for formal confirmation before you commit to the build.
What we handle
Handled as part of most basement conversions:
- Structural and ground survey
- Electrics, heating and plastering
- Party wall notices
- Lightwells and windows
- Waterproofing design (tanking or cavity drain membrane)
- Underpinning or new structure where needed
How long does it take?
The build itself usually takes 8 to 16 weeks for a cellar conversion; longer for new excavation. Allow time beforehand for drawings and approvals, usually 3 to 5 months.
Building in Luton
Many towns in the East of England have estates built since the 1970s, where garage conversions and rear extensions are popular.
Luton sits in Bedfordshire, about 18 miles south of Bedford. We cover the whole of Luton, including postcodes LU1.
How it works
- 01
Visit and measured survey
A free visit to understand the project, check access and take measurements.
- 02
Design and pricing
Design options, then a fixed quote based on the chosen drawings and specification.
- 03
Approvals in place
We handle planning, building control and neighbour notices before work starts.
- 04
Construction and completion
We build, put right any snags and hand over the building control certificate.
Questions about basement conversions in Luton
Can a basement be a bedroom?
Yes, with a suitable escape route such as a lightwell window or protected stair.
How much does a basement conversion cost in Luton?
In Luton, a basement conversion typically costs £2,000–£3,400 per m² for converting an existing cellar, including VAT at 20% (standard rate). A typical 30 m² project comes to roughly £60,000–£102,000. Your fixed price depends on the survey and drawings.
Does a basement conversion need planning permission?
Converting an existing cellar without changing the outside usually does not. New excavation, lightwells and changes visible from outside usually do.
How long does a basement conversion take in Luton?
Typically 8 to 16 weeks for a cellar conversion; longer for new excavation. Design and approvals beforehand usually take 3 to 5 months.
Do I need party wall agreements?
In England and Wales, excavating near a neighbour’s foundations usually triggers the Party Wall etc. Act 1996.