Garage Conversion Cost Guide 2026
A garage conversion is the most affordable way to add a room to your home because the shell already exists. You are essentially fitting out an existing space with insulation, heating, and proper finishes.
Cost breakdown
Basic vs high-spec conversion
A basic conversion (insulation, plasterboard, electrics, flooring, and replacing the garage door with a wall and window) costs £15,000–£25,000. A high-spec conversion with en-suite bathroom, underfloor heating, and quality finishes costs £25,000–£40,000. The difference is in the level of finish.
Key cost elements
Replacing the garage door with a wall and window (£2,000–£4,000), floor insulation and damp-proofing (£1,500–£3,000), wall insulation and plasterboard (£2,000–£4,000), electrics (£1,000–£2,500), heating (£1,000–£3,000), decoration (£1,000–£2,000), and Building Regs fees (£300–£500).
| Type | Cost Range |
|---|---|
| Single garage (basic) | £15,000–£25,000 |
| Single garage (high-spec) | £25,000–£40,000 |
| Double garage | £25,000–£45,000 |
| Detached garage | £20,000–£40,000 |
| With en-suite bathroom | +£5,000–£10,000 |
Prices based on Dorset rates, 2026
Frequently asked questions
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