Garage to Bedroom Conversion: Cost, Rules & Value
Turning an under-used garage into a bedroom is one of the best-value ways to add a room without extending. In 2026, a garage-to-bedroom conversion costs £7,000-£20,000 in the UK - a single garage is typically £7,000-£12,000 and a double £12,000-£20,000. It usually falls under permitted development, but it must meet building regs for insulation, heating, ventilation and escape. This guide compares cost, rules and value.
Garage to Bedroom: Cost, Rules & What to Weigh
A garage conversion reuses existing walls, roof and foundations, so it is far cheaper than an extension. The work is mostly insulating, infilling the door opening, adding heating and ventilation, and meeting escape and damp requirements. Here is what to compare.
Single garage to bedroom
£7,000-£12,000. Infill the door, insulate walls/floor/ceiling, plaster, add heating, flooring, window and electrics. The most common, best-value conversion.
Double garage to bedroom(s)
£12,000-£20,000. More floor area and often two rooms or a bedroom with en-suite. Higher heating, electrical and finishing cost.
Adding an en-suite
Add £3,000-£7,000. New drainage, plumbing, a compact suite and tiling. Turns a garage bedroom into a valuable guest or teen suite.
Building regulations
Always required. Covers insulation (walls, floor, roof), heating, ventilation, damp-proofing, fire safety and an escape (egress) window. Budget for the application and inspections.
Planning permission
Usually permitted development if you are not extending the footprint and it is not in a conservation area or under an Article 4 direction. Check with your council; a lawful development certificate is worth having.
Value added
A well-finished garage bedroom can add value and, importantly, a usable room. Keeping some off-street parking or garage/storage nearby protects saleability.
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