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 North Shields?
In North Shields, a basement conversion typically costs £1,700–£2,900 per m² for converting an existing cellar, including VAT at 20% (standard rate). For a typical 30 m² project that is roughly £51,000–£87,000. Prices across the North East are typically 10% below the UK average for this kind of work, which is reflected in the range for North Shields. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| Smaller project (21 m²) | £35,500–£61,000 |
| Typical project (30 m²) | £51,000–£87,000 |
| Larger project (42 m²) | £71,500–£122,000 |
| Rate per m² | £1,700–£2,900 |
Your quote will depend mainly on:
- Existing cellar or new excavation
- Party wall surveyor fees
- Waterproofing system
- 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 North Shields?
Here is how the rules work for a basement conversion 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.
If the answer is not clear-cut, we can apply for formal confirmation before you commit to the build.
What we handle
What we take care of:
- Lightwells and windows
- Underpinning or new structure where needed
- Electrics, heating and plastering
- Structural and ground survey
- Insulation, ventilation and drainage pumps
- Building control sign-off
How long does it take?
The build itself usually takes 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 North Shields
The North East has many terraced streets and post-war semis, where rear extensions and loft conversions are popular ways to gain space.
We work across North Shields and neighbouring areas such as Tynemouth, South Shields and Whitley Bay. Postcodes we cover in North Shields include NE29 and NE30.
How it works
- 01
Survey and brief
We visit, discuss your ideas and budget, and survey the property or site at no cost.
- 02
Drawings and written quote
We prepare the design and give you a written, itemised quote with inclusions and exclusions.
- 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 North Shields
How much does a basement conversion cost in North Shields?
In North Shields, a basement conversion typically costs £1,700–£2,900 per m² for converting an existing cellar, including VAT at 20% (standard rate). A typical 30 m² project comes to roughly £51,000–£87,000. Your fixed price depends on the survey and drawings.
Do I need party wall agreements?
In England and Wales, excavating near a neighbour’s foundations usually triggers the Party Wall etc. Act 1996.
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 North Shields?
Typically 8 to 16 weeks for a cellar conversion; longer for new excavation. Design and approvals beforehand usually take 3 to 5 months.
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.
