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 Leicestershire?
In Leicestershire, a basement conversion typically costs £1,800–£3,050 per m² for converting an existing cellar, including VAT at 20% (standard rate). For a typical 30 m² project that is roughly £54,000–£91,500. That range is adjusted for the East Midlands, where domestic building work typically costs around 5% below the national average. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| Smaller project (21 m²) | £38,000–£64,000 |
| Typical project (30 m²) | £54,000–£91,500 |
| Larger project (42 m²) | £75,500–£128,000 |
| Rate per m² | £1,800–£3,050 |
The main things that change the cost:
- Waterproofing system
- Party wall surveyor fees
- Existing cellar or new excavation
- Ground water and access
A guide range is only a starting point: the guide price tool gives an instant figure for your size, and a free survey turns it into a fixed quote.
Do you need planning permission for a basement conversion in Leicestershire?
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.
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:
- Lightwells and windows
- Electrics, heating and plastering
- Waterproofing design (tanking or cavity drain membrane)
- Insulation, ventilation and drainage pumps
- Structural and ground survey
- Party wall notices
How long does it take?
Expect 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 Leicestershire
In the East Midlands, many estates built since the 1960s have integral garages that convert well into a study or bedroom.
Towns we cover in Leicestershire include Leicester, Loughborough, Hinckley, Coalville, Wigston Magna and Melton Mowbray.
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 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 Leicestershire
How do you keep a basement dry?
With a waterproofing system designed to BS 8102, typically a cavity drain membrane with a sump pump, or a tanking system.
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 Leicestershire?
In Leicestershire, a basement conversion typically costs £1,800–£3,050 per m² for converting an existing cellar, including VAT at 20% (standard rate). A typical 30 m² project comes to roughly £54,000–£91,500. 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.
Do you build basement conversions in Leicestershire?
Yes. We build basement conversions across Leicestershire, including postcodes CV13, CV9, DE12, DE73 and DE74. Every project starts with a free home visit.