Covering Horsham
Our coverage around Horsham (RH12) also includes Crawley (7 miles to the north-east) and Horley.
Homes in the South East
Many South East homes are inter-war or post-war semis and detached houses with room for rear and side extensions, while historic town centres and villages bring conservation area and listed building controls.
What does a basement conversion involve?
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.
- Lightwells and windows for daylight and escape
- Ventilation, heating and electrics
- Finished floors, walls and ceilings
What will a basement conversion cost?
Indicative costs for basement and cellar conversions. London and the South East usually sit towards the top of each range.
| 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 |
Do you need permission for a basement conversion in Horsham?
In England we deal with the council’s planning team for permission or a lawful development certificate, with building control (the council or a registered building control approver) for inspections, and with neighbours under the Party Wall etc. Act 1996 where it 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 can change the price or programme?
- Groundwater levels drive the waterproofing design and cost.
- New basements nearly always involve the Party Wall Act in England and Wales.
How does the project run?
- Start with a conversation. A short call or the online form is enough for us to understand what you want to build.
- We visit and measure. A surveyor checks the house, the boundaries and the ground, and discusses what is realistic.
- Design and fixed price. You get drawings and a written price for the agreed specification before anything is ordered.
- Build and hand over. Our teams build to the programme, building control inspects, and you get the completion paperwork at the end.
Questions about a basement conversion in Horsham
How long does it take?
About 6 to 12 weeks for a cellar conversion and 16 to 30 weeks for a new basement.
Will my neighbours be affected?
New basements usually need party wall agreements. We handle the notices and surveyors.
Can you visit a house in Horsham to quote?
Yes. After a short call we arrange a site visit to measure up and agree what the design needs to do, then send a written price.
Also covering
- Basement and cellar conversions in Crawley
- Basement and cellar conversions in Horley
- Basement and cellar conversions in Haywards Heath
- Basement and cellar conversions in Burgess Hill
Learn more about basement and cellar conversions, or see every project we cover in Horsham.