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 Ashton in Makerfield?
In Ashton in Makerfield, a basement conversion typically costs £1,800–£3,000 per m² for converting an existing cellar, including VAT at 20% (standard rate). For a typical 30 m² project that is roughly £54,000–£90,000. Prices across the North West are typically 6% below the UK average for this kind of work, which is reflected in the range for Ashton in Makerfield. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| Smaller project (21 m²) | £38,000–£63,000 |
| Typical project (30 m²) | £54,000–£90,000 |
| Larger project (42 m²) | £75,500–£126,000 |
| Rate per m² | £1,800–£3,000 |
Your quote will depend mainly on:
- Waterproofing system
- Floor lowering and underpinning
- Existing cellar or new excavation
- Ground water and access
Use the guide price tool to see how size and specification change the figure, then ask for a written, itemised quote.
Do you need planning permission for a basement conversion in Ashton in Makerfield?
Approvals for a basement conversion in Ashton in Makerfield follow the rules for 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
What we take care of:
- Waterproofing design (tanking or cavity drain membrane)
- Party wall notices
- Electrics, heating and plastering
- Insulation, ventilation and drainage pumps
- Lightwells and windows
- Structural and ground survey
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 Ashton in Makerfield
The North West has many brick terraces and inter-war semis, where kitchen extensions and dormer loft conversions add space without moving.
From WN4 outwards, we take on projects throughout Ashton in Makerfield and the surrounding parts of Merseyside.
How it works
- 01
Survey and brief
We visit, discuss your ideas and budget, and survey the property or site at no cost.
- 02
Design and pricing
Design options, then a fixed quote based on the chosen drawings and specification.
- 03
Approvals in place
We handle planning, building control and neighbour notices before work starts.
- 04
Build and handover
Work follows the agreed programme, with inspections along the way and a completion certificate at the end.
Questions about basement conversions in Ashton in Makerfield
How much does a basement conversion cost in Ashton in Makerfield?
In Ashton in Makerfield, a basement conversion typically costs £1,800–£3,000 per m² for converting an existing cellar, including VAT at 20% (standard rate). A typical 30 m² project comes to roughly £54,000–£90,000. Your fixed price depends on the survey and drawings.
Can a basement be a bedroom?
Yes, with a suitable escape route such as a lightwell window or protected stair.
How long does it take?
A cellar conversion takes around 8 to 16 weeks; new basements take longer.
Who approves a basement conversion in Ashton in Makerfield?
Planning matters in Ashton in Makerfield go to the council covering your address, and the work needs building control approval. We prepare and submit the applications for you.
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.