Cost calculator
Garage conversion cost calculator
Garage conversions look simple and often are — but the existing structure was never built to habitable standards. Floor level, damp proofing and insulation are where the real work sits, and where cheap quotes cut corners.
Internal area of the garage being converted.
Broad trade availability keeps day rates near the national average.
Estimated range, ex VAT
£16,000 – £31,500
- Labour (typical)
- £12,500
- Materials (typical)
- £11,500
Guidance only. A real quotation depends on site conditions, specification and access — which is exactly what an independent review of your own quote will tell you.
What affects the cost
Floor level and build-up
Garage slabs usually sit lower than house floors and lack a damp proof membrane. A new insulated floor is nearly always required.
Damp and wall construction
Single skin walls need internal lining or a new inner leaf to hit thermal and damp standards.
Garage door infill
New foundations may be needed under the infill wall; matching brickwork on an older house is a skilled job.
Services
Heating extension, new circuits from the consumer unit and ventilation to building regulations.
Integral vs detached
Integral garages are far cheaper — a detached garage conversion needs its own heating, services and often planning permission.
Regional pricing differences
Materials cost roughly the same everywhere in the UK; labour does not. Use the region selector above to apply a local index — London and the South East typically run 15–30% above the national average, while the North East, Northern Ireland and Yorkshire sit below it.
Labour vs materials
Roughly 52% of this type of work is labour and 48% materials. Labour is around half. Materials are dominated by insulation, plasterboard, screed and the new window or wall infill.
Common hidden costs
- Structural lintel and foundation work at the door opening, rarely priced until the door is removed.
- Ceiling height loss from the new floor build-up, which can push you under comfortable head height.
- Building control notification and the completion certificate — needed at resale.
- Loss of storage means garden storage or a shed becomes an unbudgeted extra.
How to save money
- Keep the new window in the existing door opening rather than cutting a new one.
- Extend the existing heating circuit instead of installing electric heating that costs more to run.
- Retain the concrete slab where levels allow, and use a thin insulated overlay rather than digging out.
- Bundle the work with other trades already on site to share setup and skip costs.
Frequently asked questions
How much does a garage conversion cost?
Typically £13,000–£25,000 ex VAT for an integral single garage in 2026, depending on floor and wall works.
Do I need planning permission?
Usually not for an integral garage, but permitted development rights may have been removed on newer estates. Building regulations always apply.
Does a garage conversion add value?
Usually yes, when it creates a genuinely useful room. Removing the only off-street parking can work against you in cities.
How long does it take?
Three to five weeks for a standard single garage.
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