Cost of a Garage Conversion in the UK (2025)
A garage conversion costs £15,000–£30,000. It is one of the best-value ways to add living space — no foundations needed and usually no planning permission required.
Integral vs detached garage conversions
An integral garage (attached to the house, sharing at least one wall) is the simplest and cheapest to convert — it typically already has a damp proof course, electricity supply, and easy access to the main house. A detached garage conversion requires more work to make habitable: insulation, heating, and a proper connection to the main house drainage and electrical systems.
Planning permission for garage conversions
Most integral garage conversions are Permitted Development and do not require planning permission, provided the exterior appearance is not significantly altered. Converting a detached garage may require permission depending on its size and location. Always check with your local planning authority or ask your builder to confirm before starting.
Cost Breakdown
All prices are indicative UK averages for 2025. Actual costs vary by location, specification, and contractor. London and South East rates are typically 20–35% higher.
| Item | Low | High |
|---|---|---|
| Basic integral garage conversion | £12,000 | £20,000 |
| Integral conversion with en suite | £18,000 | £28,000 |
| Detached garage conversion | £18,000 | £35,000 |
| Garage into home office | £8,000 | £18,000 |
| Garage into utility room | £6,000 | £14,000 |
| Structural beam (if wall removed) | £2,000 | £6,000 |
What Affects the Cost?
- ✓Integral vs detached garage
- ✓Intended use — living space vs office vs utility
- ✓Whether an en suite is added
- ✓Insulation requirements — floor, walls, roof
- ✓Windows and doors (replacing the garage door)
- ✓Heating connection to main system
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Post a Job — It's FreeFrequently Asked Questions
Does converting a garage add value?
Yes — converting an integral garage to a habitable room typically adds £10,000–£25,000 to property value, depending on location. Creating an additional bedroom or home office is particularly valuable.
Do I need Building Regulations approval for a garage conversion?
Yes — even if planning permission is not required, Building Regulations approval is needed. This covers structural, fire safety, insulation, ventilation, and electrics. Your builder will manage this process.
Will I lose parking by converting my garage?
Potentially — this can affect planning applications in some areas and may impact your home insurance. Check your insurance policy and consider whether off-street parking is important to future buyers.
How long does a garage conversion take?
A standard integral garage conversion takes 3–6 weeks. More complex projects with en suites or structural alterations take 6–10 weeks.