Converting your garage is one of the most cost-effective ways to add usable space to your home — and with UK property prices where they are, plenty of homeowners are looking inward rather than moving. So what does a garage conversion cost, and what’s actually involved? This guide covers garage conversion cost in 2026, planning permission and building regulations, timelines, and whether the work will add value.
What is a garage conversion?
A garage conversion turns existing garage space — attached, integral or detached — into a habitable room, such as a bedroom, home office, playroom, gym or utility room. Because you’re working within a structure that already exists, it usually costs less and takes less time than a full extension.
How much does a garage conversion cost?
In the UK, a garage conversion typically ranges from £10,000 to £25,000, depending on the size of the garage, what you’re turning it into, and how much structural and services work is needed. The table below sets out what to expect at each level.
| Type of conversion | What it usually covers | Typical cost |
|---|---|---|
| Basic single garage | Home office or playroom — insulation, flooring, plastering, windows and doors, electrics | £10,000 – £15,000 |
| Mid-range | As above, plus an en-suite or small kitchenette | £15,000 – £20,000 |
| High-spec or integral with new services | Full fit-out, rewiring, heating and higher-end finishes | £20,000 – £25,000+ |
| Detached garage | Its own roof and walls, new utility connections, and often planning permission | £18,000 – £30,000+ |
Regional pricing varies a fair bit — London and the South East command higher rates than Wales or the North of England, so treat the figures above as a national guide rather than a fixed quote.
What’s included in those costs?
A standard budget usually covers insulation, flooring, plastering, windows and doors, electrical work, and any plumbing, alongside the architectural drawings and building regulations approval you’ll need before work starts.
Do you need planning permission for a garage conversion?
In both England and Wales, most integral and attached garage conversions fall under permitted development rights and don’t need planning permission, provided the work is internal and doesn’t materially change the footprint or external appearance. You’re more likely to need permission if your home is in a conservation area, if permitted development rights have been removed (for example by an Article 4 direction), if you’re making significant external changes, or if you’re converting a detached garage into a separate dwelling. It’s always worth checking with your local council before you begin.
Building regulations: what you must comply with
Unlike planning permission, building regulations approval is always required for a garage conversion. The regulations cover structural stability, insulation, ventilation, fire safety, electrical and plumbing compliance, and a safe means of escape. This applies whether you’re in England or Wales, so a habitable garage conversion always needs to be signed off by building control.
Integral, attached or detached: does it make a difference?
Integral garage
Built within the main house. This is the easiest and most cost-effective type to convert, as it mainly needs insulation and interior work.
Attached garage
Shares a wall with the house but has its own roof. Slightly more involved than an integral garage, but usually still permitted development.
Detached garage
The most complex option. It typically needs new utility connections and, where you’re creating a separate annex, planning permission. Costs here tend to reach £18,000–£30,000+.
How long does a garage conversion take?
For a standard integral or attached garage, the whole process usually takes 12–18 weeks from instruction to completion:
- Architectural drawings: 2–4 weeks
- Building regulations application: 5–8 weeks
- Build on site: 3–6 weeks
Will a garage conversion add value to your home?
A converted garage that adds a bedroom can increase property value by around 10–15%. Home offices and playrooms add value too, if slightly less. In high-demand areas the uplift can exceed the cost of the work. The one thing to weigh up is parking — losing off-road parking can reduce value in areas where it’s hard to come by.
Do you still need a dropped kerb or parking?
Converting a garage removes that off-road parking space, so some local authorities will want to see that you have adequate alternative parking before approving any related changes. It’s worth confirming your council’s position early.
Garage conversion ideas: what can you do with the space?
- Extra bedroom
- Home office
- Playroom or hobby room
- Gym
- Utility room or boot room
- Annex for an elderly relative
- Cinema room
Getting the drawings done: why it matters
Even when you don’t need planning permission, you’ll need proper architectural drawings to submit a building regulations application. Good drawings specify insulation, structural details, window and door positions, electrical layouts and drainage routes — which keeps building control moving and stops your builder padding their quote with contingencies for the unknowns.
Ready to get started?
A garage conversion is good value, relatively fast, and usually straightforward when it’s planned properly. At Arkiplan we produce your drawings for a fixed price, with no hourly billing, so you know exactly where you stand before work begins. If you’re weighing up a conversion, we’re happy to talk it through.