Garage Conversion Costs UK 2026: Complete Guide
A garage conversion is one of the most cost-effective ways to add a bedroom, office or living space. Here is what it costs and what is involved.
Garage Conversion Costs
| Conversion Type | Average Cost |
|---|---|
| Basic single garage (bedroom/office) | £5,000–£10,000 |
| Mid-range single garage (en-suite) | £10,000–£15,000 |
| Double garage conversion | £12,000–£25,000 |
| Garage studio/gym | £7,000–£18,000 |
| Garage to annexe | £15,000–£30,000 |
The main costs are: insulation and damp proofing (floor, walls, ceiling), new front wall (replacing the garage door), heating and electrics, and finishing (plastering, flooring, decoration).
Planning Permission and Building Regs
Planning permission — Usually not required as garage conversions are classed as permitted development (changing use of an existing space), though the work still needs building regulations approval and a builder who will certify it. Check with your local council if:
- You are in a conservation area
- Your property is listed
- There are conditions on your original planning consent
Building regulations — Always required. Your conversion must meet standards for structural stability, fire safety, insulation, ventilation and drainage. You will need building control sign-off.
Parking — Some councils require that off-street parking is maintained. Losing a garage may be an issue if you have no driveway.
Frequently Asked Questions
Does a garage conversion add value?
How long does a garage conversion take?
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