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 Wigston Magna?
In Wigston Magna, 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. We start from a UK-wide guide and adjust it for the East Midlands, where labour and materials are typically about 5% below 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 |
What moves the price most:
- Ground water and access
- Waterproofing system
- Existing cellar or new excavation
- Lightwells
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 Wigston Magna?
Before anything is built in Wigston Magna, 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.
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.
We check this for your address before design work starts, so there are no surprises later.
What we handle
The work we manage on a basement conversion:
- Electrics, heating and plastering
- Structural and ground survey
- Building control sign-off
- Insulation, ventilation and drainage pumps
- Lightwells and windows
- Party wall notices
How long does it take?
Allow 8 to 16 weeks for a cellar conversion; longer for new excavation. Design and approvals come first and typically take 3 to 5 months, depending on the approval route.
Building in Wigston Magna
In the East Midlands, many estates built since the 1960s have integral garages that convert well into a study or bedroom.
Our Wigston Magna coverage includes postcode districts LE2 and LE18, and we also work in nearby places such as Oadby, Leicester and Earl Shilton.
How it works
- 01
Visit and measured survey
A free visit to understand the project, check access and take measurements.
- 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
Construction and completion
We build, put right any snags and hand over the building control certificate.
Questions about basement conversions in Wigston Magna
Who approves a basement conversion in Wigston Magna?
Planning matters in Wigston Magna go to the council covering your address, and the work needs building control approval. We prepare and submit the applications for you.
Can a basement be a bedroom?
Yes, with a suitable escape route such as a lightwell window or protected stair.
Is new excavation worth it?
It can be in high-value areas, but costs are high. We give a feasibility view before design starts.
How much does a basement conversion cost in Wigston Magna?
In Wigston Magna, 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.
How long does it take?
A cellar conversion takes around 8 to 16 weeks; new basements take longer.
