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 Stourport-on-Severn?
In Stourport-on-Severn, a basement conversion typically costs £1,850–£3,100 per m² for converting an existing cellar, including VAT at 20% (standard rate). For a typical 30 m² project that is roughly £55,500–£93,000. Prices in the West Midlands sit near the national average for this kind of work, and the range for Stourport-on-Severn reflects that. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| Smaller project (21 m²) | £39,000–£65,000 |
| Typical project (30 m²) | £55,500–£93,000 |
| Larger project (42 m²) | £77,500–£130,000 |
| Rate per m² | £1,850–£3,100 |
The main things that change the cost:
- Lightwells
- Floor lowering and underpinning
- Existing cellar or new excavation
- Party wall surveyor fees
A guide range is only a starting point: the guide price tool gives an instant figure for your size, and a free survey turns it into a fixed quote.
Do you need planning permission for a basement conversion in Stourport-on-Severn?
The approval route for Stourport-on-Severn is set by planning law 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.
Our first visit includes a check of your planning history, so you know the route before paying for drawings.
What we handle
Handled as part of most basement conversions:
- Underpinning or new structure where needed
- Building control sign-off
- Party wall notices
- Insulation, ventilation and drainage pumps
- Structural and ground survey
- Lightwells and windows
How long does it take?
Build time is typically 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 Stourport-on-Severn
Across the West Midlands, inter-war and post-war semis make up much of the housing, giving good scope for two-storey side extensions and hip-to-gable lofts.
Our Stourport-on-Severn coverage includes postcode districts DY13, and we also work in nearby places such as Kidderminster, Droitwich and Bromsgrove.
How it works
- 01
Free visit
We look at the property, talk through what you want and measure up. There is no charge and no obligation.
- 02
Drawings and written quote
We prepare the design and give you a written, itemised quote with inclusions and exclusions.
- 03
Approvals in place
We handle planning, building control and neighbour notices before work starts.
- 04
Construction and completion
We build, put right any snags and hand over the building control certificate.
Questions about basement conversions in Stourport-on-Severn
Do you build basement conversions in Stourport-on-Severn?
Yes. We build basement conversions across Stourport-on-Severn, including postcodes DY13. Every project starts with a free home visit.
Do I need party wall agreements?
In England and Wales, excavating near a neighbour’s foundations usually triggers the Party Wall etc. Act 1996.
Is new excavation worth it?
It can be in high-value areas, but costs are high. We give a feasibility view before design starts.
How long does it take?
A cellar conversion takes around 8 to 16 weeks; new basements take longer.
How much does a basement conversion cost in Stourport-on-Severn?
In Stourport-on-Severn, a basement conversion typically costs £1,850–£3,100 per m² for converting an existing cellar, including VAT at 20% (standard rate). A typical 30 m² project comes to roughly £55,500–£93,000. Your fixed price depends on the survey and drawings.
