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 Galashiels?
In Galashiels, 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 Scotland sit near the national average for this kind of work, and the range for Galashiels 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:
- Existing cellar or new excavation
- Agreements with neighbours on shared walls
- Floor lowering and underpinning
- Ground water and access
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 Galashiels?
Whether you need planning permission depends on your house and its location in Scotland. In Scotland converting an existing cellar may not need planning permission, but a building warrant is needed, and new excavation usually needs planning permission.
In Scotland a building warrant is needed before work starts on most extensions, loft conversions and conversions. It is issued by the council’s building standards service. When the work is finished, a completion certificate is submitted and accepted by the council after inspection.
Our first visit includes a check of your planning history, so you know the route before paying for drawings.
What we handle
On a typical basement conversion we handle:
- Lightwells and windows
- Underpinning or new structure where needed
- Written agreement with neighbours on shared walls
- Insulation, ventilation and drainage pumps
- Electrics, heating and plastering
- Structural and ground survey
How long does it take?
Build time is typically 8 to 16 weeks for a cellar conversion; longer for new excavation. Design and approvals come first and typically take 3 to 5 months, depending on the approval route.
Building in Galashiels
In Scotland, bungalows and one-and-a-half-storey homes are common, so dormer conversions are a popular way to add bedrooms.
From TD1 outwards, we take on projects throughout Galashiels and the surrounding parts of the Scottish Borders.
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
Planning or permitted development confirmation, building regulations and any party wall matters.
- 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 Galashiels
Do you build basement conversions in Galashiels?
Yes. We build basement conversions across Galashiels, including postcodes TD1. Every project starts with a free home visit.
Do I need planning permission for a basement conversion in Galashiels?
In Scotland converting an existing cellar may not need planning permission, but a building warrant is needed, and new excavation usually needs planning permission.
How long does it take?
A cellar conversion takes around 8 to 16 weeks; new basements take longer.
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.
Can a basement be a bedroom?
Yes, with a suitable escape route such as a lightwell window or protected stair.
How much does a basement conversion cost in Galashiels?
In Galashiels, 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.
