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 Hastings?
In Hastings, a basement conversion typically costs £2,150–£3,600 per m² for converting an existing cellar, including VAT at 20% (standard rate). For a typical 30 m² project that is roughly £64,500–£108,000. We start from a UK-wide guide and adjust it for the South East, where labour and materials are typically about 12% above average. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| Smaller project (21 m²) | £45,000–£75,500 |
| Typical project (30 m²) | £64,500–£108,000 |
| Larger project (42 m²) | £90,500–£151,000 |
| Rate per m² | £2,150–£3,600 |
Your quote will depend mainly on:
- Waterproofing system
- Lightwells
- Floor lowering and underpinning
- Existing cellar or new excavation
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 Hastings?
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.
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:
- Structural and ground survey
- Building control sign-off
- Underpinning or new structure where needed
- Party wall notices
- Insulation, ventilation and drainage pumps
- Waterproofing design (tanking or cavity drain membrane)
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 Hastings
The South East has a broad mix of housing, from Victorian terraces in the towns to post-war semis and newer estates, so extension types vary street by street.
We work across Hastings and neighbouring areas such as Bexhill-on-Sea, Hailsham and Eastbourne. Postcodes we cover in Hastings include TN34.
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
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 Hastings
Who approves a basement conversion in Hastings?
Planning matters in Hastings go to the council covering your address, and the work needs building control approval. We prepare and submit the applications for you.
Is new excavation worth it?
It can be in high-value areas, but costs are high. We give a feasibility view before design starts.
Can a basement be a bedroom?
Yes, with a suitable escape route such as a lightwell window or protected stair.
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 much does a basement conversion cost in Hastings?
In Hastings, a basement conversion typically costs £2,150–£3,600 per m² for converting an existing cellar, including VAT at 20% (standard rate). A typical 30 m² project comes to roughly £64,500–£108,000. Your fixed price depends on the survey and drawings.