Extensions & Conversions · Updated 2026
Garage conversion cost
Typical range£6,000–£50,000· Average integral garage conversion
Integral and detached garage conversion costs for 2025. In the UK, expect to pay between £6,000 and £50,000, with the typical project around £12,000 (average integral garage conversion). Regional variation, specification tier and site access conditions all shift the final quote.
Quick answer: Garage conversion cost in the UK typically costs between £6,000 and £50,000 (Average integral garage conversion). London and the South East run 20–35% above this range; the North, Wales and most of Scotland sit 5–15% below.
Homeowners researching this typically also price up garden room cost. For wider context, browse our bathroom pricing, kitchen pricing and boiler & heating costs.
Cost table
Indicative price ranges (UK, GBP)
| Item | Typical range (GBP) |
|---|---|
Basic integral garage conversion — Insulation, plasterboard, floor, electrics only | £6,000–£12,000 |
Full integral conversion (room) — Full fit-out, toilet, high spec finish | £10,000–£20,000 |
Detached garage conversion — Requires new services, more complex | £15,000–£35,000 |
Double garage conversion — Two rooms or large open plan | £16,000–£40,000 |
Garage conversion to annexe — Self-contained unit with kitchen/bathroom | £20,000–£50,000 |
Labour costs
Labour typically accounts for 50% of the total project cost in the UK.
Labour line items
| Item | Typical range (GBP) |
|---|---|
Builder (structural work) | £3,000–£8,000 |
Electrician | £800–£2,500 |
Plumber (if bathroom added) | £1,500–£4,000 |
Plasterer | £600–£1,500 |
Decorator | £500–£1,200 |
Building regulations inspector | £150–£400 |
Materials costs
Materials and fittings make up the remainder of the budget, with specification tier driving most of the variation.
Materials & fittings
| Item | Typical range (GBP) |
|---|---|
Insulation (walls, floor, ceiling) | £800–£2,500 |
Plasterboard & skim | £600–£1,500 |
Concrete floor / screed | £500–£1,500 |
New door / window | £500–£2,000 |
Electrical fittings | £400–£1,200 |
Heating (radiator or UFH) | £500–£2,500 |
Factors affecting cost in the UK
- ·Region — London and the South East run 15–30% above national averages.
- ·Specification tier — premium materials and finishes can double the base cost.
- ·Access and site conditions — flats, restricted parking and listed buildings add time.
- ·Scope changes mid-project — late design decisions are the biggest cost overrun driver.
- ·Trade availability — quotes rise 10–20% in peak spring and summer months.
Ways to reduce cost
- ·Keep the existing roof if it's sound rather than re-pitching.
- ·Block up the garage door opening with masonry rather than a full window/wall feature.
- ·Extend existing heating from the adjacent room rather than adding a new boiler zone.
- ·Use a builder under a JCT minor works contract rather than a specialist garage conversion company.
- ·Combine the conversion with a planned re-decoration of adjoining rooms to share trades.
Frequently asked questions
- Do I need planning permission to convert a garage?
- Converting an integral (attached) garage is usually permitted development and does not require planning permission. However, if the garage is detached, listed, in a conservation area, or in a flat or maisonette, you will typically need full planning permission.
- How long does a garage conversion take?
- A basic integral garage conversion takes 3–6 weeks. A full fit-out with toilet and utility room takes 6–10 weeks. Detached garage conversions with new services may take 10–16 weeks.
- Does a garage conversion add value?
- Yes — converting a garage into a habitable room typically adds 10–20% to property value and costs less than a full extension. However, losing garage parking can be a negative in areas where off-street parking is scarce.
- Do I need building regulations approval?
- Yes, always — garage conversions are notifiable works under building regulations. You'll need to ensure insulation, structural, fire safety, ventilation, and electrical standards are met. Your local authority building control or a private approved inspector can oversee this.
- Can a converted garage be used as a bedroom?
- Yes, subject to meeting building regulations for habitable rooms: minimum ceiling height of 2.1m, adequate natural light and ventilation, adequate insulation (thermal and acoustic), and appropriate fire safety.