Covering Seaford
Alongside Seaford, we also cover Rottingdean, Eastbourne (8 miles to the east) and Hailsham.
Homes in the South East
The South East has a lot of 1930s and post-war semi-detached housing, well suited to rear extensions and hip-to-gable loft conversions, alongside period properties in conservation areas that need a more careful design.
What do you get with a basement conversion?
A basement conversion turns an existing cellar into dry, usable rooms, or excavates a new basement under a house. Converting an existing cellar is far simpler and cheaper than digging a new one, and often does not need planning permission.
- Waterproofing design and installation
- Lightwells and windows for daylight and escape
- Finished floors, walls and ceilings
What is the guide price for a basement conversion in Seaford?
Typical ranges for basement and cellar conversions. Ground conditions, access and specification move the final figure, which we fix in writing before work starts.
| Basement and cellar conversions | Guide price incl. VAT |
|---|---|
| Existing cellar conversion | £1,900 to £3,000 per m² |
| New basement excavation | £4,200 to £6,600 per m² |
How is a basement conversion approved in Seaford?
Projects in England go through two separate checks. Planning (or confirmation that the work is permitted development) comes from the district, borough or unitary council, and building regulations approval comes from the council’s building control team or a registered building control approver. Where work touches a shared wall or digs near a neighbour’s foundations, the Party Wall etc. Act 1996 applies.
Converting an existing cellar with no external changes usually does not need planning permission in England. Digging a new basement or adding a lightwell often does, and many councils have basement policies.
What should Seaford homeowners check first?
- Groundwater levels drive the waterproofing design and cost.
- A pump for the drainage system needs a battery back-up.
What are the steps?
- Send us the details. Give us a postcode, a rough idea of size and some photos, by phone, form or the guide price tool.
- Survey at your house. We look at the existing structure, services and access, and agree what the design needs to achieve.
- Drawings, approvals, written quote. We prepare the design, apply for the approvals it needs, and give you a fixed price in writing.
- Construction and completion. One site lead co-ordinates every trade through to the building control certificate.
Basement and cellar conversions: common questions
Does a cellar conversion need planning permission?
Usually not if nothing changes outside. New basements and lightwells often do.
Will my neighbours be affected?
New basements usually need party wall agreements. We handle the notices and surveyors.
Do you work in Seaford?
Yes. Seaford is within our coverage for basement and cellar conversions, along with nearby Rottingdean and Eastbourne.
Also covering
- Basement and cellar conversions in Rottingdean
- Basement and cellar conversions in Eastbourne
- Basement and cellar conversions in Hailsham
- Basement and cellar conversions in Brighton
Learn more about basement and cellar conversions, or see every project we cover in Seaford.

