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 Nottingham?
In Nottingham, 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 biggest cost drivers are:
- Floor lowering and underpinning
- Waterproofing system
- Ground water and access
- Lightwells
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 Nottingham?
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
On a typical basement conversion we handle:
- Lightwells and windows
- Insulation, ventilation and drainage pumps
- Electrics, heating and plastering
- Building control sign-off
- Underpinning or new structure where needed
- Structural and ground survey
How long does it take?
The build itself usually takes 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 Nottingham
In the East Midlands, many estates built since the 1960s have integral garages that convert well into a study or bedroom.
We work across Nottingham and neighbouring areas such as West Bridgford, Arnold and Hucknall. Postcodes we cover in Nottingham include NG1, NG3 and NG7.
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
Build and handover
Work follows the agreed programme, with inspections along the way and a completion certificate at the end.
Questions about basement conversions in Nottingham
How much does a basement conversion cost in Nottingham?
In Nottingham, 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.
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 long does a basement conversion take in Nottingham?
Typically 8 to 16 weeks for a cellar conversion; longer for new excavation. Design and approvals beforehand usually take 3 to 5 months.
Can a basement be a bedroom?
Yes, with a suitable escape route such as a lightwell window or protected stair.