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Thinking about converting your garage in 2026?
Thinking About Converting Your Garage in 2026? Here’s What It Might Cost!
Decided to post this after seeing a few people commenting on questions and fears they have about converting their garage.
If you’re like many homeowners wondering whether that under-used garage could be transformed into extra living space – office, bedroom, playroom or something else – here’s a quick snapshot of what you might expect to spend in the UK this year
Typical cost range: Most garage conversion projects fall roughly between £10,000 and £20,000 for a standard single garage – depending on size finish level and what you’re planning to use the space for. Bigger or more complex projects (e.g., adding a bathroom, kitchen or high-end finishes) can push the price £20,000+.
Double garages. If you’re converting a double garage or attaching extra space costs can often be £20,000 to £40,000+ – especially if you’re creating something more luxurious.
What influences the cost?
Size and layout of the garage
Insulation, electrics & plumbing work
Level of finish and fixtures
Whether you need new doors/windows or structural changes
Building regulations compliance fees
Good to know. Most garage conversions don’t require full planning permission (especially if the external structure doesn’t change) but building regulations approval is usually needed to make the space legally habitable and that cost (and paperwork) should be factored into your budget.
If you’re seriously considering this the best next step is to get a few detailed quotes every garage and plan is different.
Thinking about doing one yourself or have recent conversion experience? Drop your tips or questions below!
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5 Replies
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I was just searching for this and the first this was the first answer that came up!
How much would a treble garage converted into a granny annex cost?
1 bedroom
1 lounge with kitchen
small bathroom with shower
I’ve been trying to get builders out (i’m in Horsham) but not had any luck in getting a quote yet.
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Hi Gemma, a triple garage conversion into a self-contained annex is a great use of the space
Very rough ballpark you’re probably looking somewhere in the region of £60k-£100k+ depending on spec and what’s involved. The main cost drivers will be things like insulation upgrades drainage for the bathroom/kitchen heating system electrics and whether you need to upgrade the structure (roof walls foundations etc).
Because you’re essentially creating a small dwelling it can push costs up compared to a standard garage conversion. You may also need to factor in planning permission and building regs especially for an annex.
If you’re struggling to get builders out it’s quite common at the moment worth trying local recommendations smaller builders or even approaching architects/architectural technicians who often have builder contacts.
If it helps, I’ve put together a garage conversion guide that breaks down costs and what’s involved happy to send you the link if you want
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I’d love to see the guide, thanks
Should I get out an architect first of all?
I was thinking it may be around 60 to 70k, so that reflects in what you’ve said.
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Yes, I’d usually recommend speaking to an architect or architectural technician early on especially for something like an annex. They can help you get the layout right make the most of the space and advise on things like planning permission and building regs.
That said if you’re fairly clear on the layout already you could also get a couple of builders round first to get a rough idea on costs and feasibility but for a self-contained space having proper drawings tends to make the whole process much smoother.
And yes, your £60-70k estimate isn’t unrealistic at all for a basic spec but it can creep up depending on finishes and how complex the plumbing/heating side is.
Shout if you’ve got any questions once you’ve had a look through the guide 😊
Here’s the link to my Garage Conversion Guide –
https://martinpeat.gumroad.com/l/lercf
It’s designed to take you from the start to building control sign off. Whether you are doing the work yourself or getting builders in you can make sure everything that’s being done is building control compliant so that it doesn’t cost you more money further down the road
Hope this helps
martinpeat.gumroad.com
Garage Conversion Planning & Building Control (UK)
If you’re planning a garage conversion in the UK, planning rules and Building Control can be confusing, inconsistent, and easy to get wrong.I’m currently converting my own garage and created this guide to make sure I didn’t miss anything important … Continue reading
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Thats perfect,
I’ll take a good luck at the site.
Thank you very much!
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