UK Renovation Budget Planner
Estimate garage conversion costs in pounds sterling (GBP). Calculate budgets for single, double, integrated or detached garages into habitable living rooms, bedrooms, or offices.
UK Cost Benchmarks
Average installed costs across typical specifications. Figures include materials and standard UK tradesperson labour.
| Specification / Option | Typical UK Fitted Range | Characteristics & Considerations |
|---|---|---|
| Standard Integrated Single Garage Conversion | £900 – £1,300 per m² | Infilling garage door, damp-proof membrane, wall/floor insulation, electrics |
| Detached Garage Habitable Living Space | £1,300 – £1,800 per m² | Requires independent service connections, structural lintels, high-spec insulation |
| Double Garage Conversion (Living Room / Annex) | £1,100 – £1,650 per m² | Large-span structural adaptation, multiple window openings, heating extension |
HomeProjects.money editorial team reviewed this page on 6 August 2026. HomeProjects.money is an independent planning tool, not a contractor, surveyor or building-control body. Listed sources inform the context and checking process; calculator ranges remain editorial planning assumptions that must be tested against written local quotes.
Planning assumptions
Insulation, basic finishes, common electrical work and a standard window or door allowance. A garage conversion combines fabric, structure, fire safety, ventilation, heating, electrical work and an appropriate escape strategy. Floor level, damp, ceiling height and the relationship to the house should be assessed before layout decisions.
Single-skin walls, uninsulated slabs, damp, low ceilings and roof defects can make the existing shell more expensive to upgrade than its appearance suggests.
Replacing the garage door, forming windows or internal openings and matching external finishes can require structure, weathering and planning checks.
A bedroom, office, bathroom or kitchen has different drainage, ventilation, heating, electrical, fire and egress requirements.
Scope decisions
Cost comparisons are useful only when every contractor prices the same performance, preparation and finishing requirements.
An office, playroom or living space with limited new plumbing is generally simpler than wet accommodation.
Requires careful escape, ventilation, thermal comfort, privacy and accessibility planning.
Adds kitchen, bathroom, drainage and possible planning or zoning issues and should not use a basic conversion allowance.
Country requirements
The calculator never mixes UK and US prices. The guidance below also follows the selected country; local authorities and code officials remain the definitive source.
Most internal garage conversions fall under Permitted Development unless planning conditions removed permitted rights or you live in a conservation area. Building Regulations approval (Part L insulation, damp-proofing, ventilation) is always mandatory.
Looking for US project planning in USD? Browse our US States & Cities Cost Directory or review our US Home Improvement Planning Guides.
Quote checklist
Common questions
Not automatically. Level, damp protection, insulation, structure and finished ceiling height must be assessed.
No. A dwelling unit adds substantial design, services, zoning and life-safety scope.
Possibly. The answer depends on location, property history, use, parking, external changes and local restrictions.
Sources and checks
These sources support regulatory and market context. They do not publish the calculator's exact range and are not presented as contractor quotations.