Garage conversion

[Brumbies]

Has anyone converted their detached single garage into a studio flat? I'm thinking along those lines, wondering do I need planning, rough cost etc

To rent out?

That sounds a bit grim :(

Yes you'd need planning permission. It might be hard to get, planners don't like changing the use of a separate garage. Is it in front of your house, beside or behind? That could make a difference.

You'd need to add heating, power, insulation etc. to building regs standards. If it's a single skin brick garage then it would take more insulating.

Oh and you'd need to add water supply and drainage presumably?

No idea of cost but friends have done it for there son
there was a small utility room off garage that’s now a shower room
small run of kitchen units across the back wall
they originally had a sofa bed but t never got folded away so have a bed with a couple of ikea armchairs
absolutely nothing grim about

Yes you would need pp. And given that you'd need heating, windows, plumbing, a bathroom, and to make all the fabric of the building habitable standard I can't imagine it would cost less than 50 grand.
But honestly I can't see you getting pp for this.

Having lived in a studio flat that was about 10ft by 12 (plus shower room), I beg to differ. It was very, very grim.

Maybe it’s something a teen/twenties can easily cope with. In your thirties it’s absolutely miserable.

For our son

It's detached behind the house

I read somewhere if we change internally but not the footprint we don't need planning

It's change of use. Planning permission needed if it will be a separate dwelling

https://www.planningportal.co.uk/permission/common-projects/garage-conversion/planning-permission

If it's just for a family member, lots of people add bits into their garage, unless you're going to be doing a lot of structural work I'd probably just go ahead.
You can always apply for retrospective planning if there's an issue & it happens to be under 4 years from now! (The council can't challenge a building used for living in 4 years after its been converted - look at the 4 year rule), but I believe this is being changed to 10 years so worth checking out.
NB if you wanted to get planning consent you should go ahead, I'm just saying lots of people don't especially if your ds might not use it all of the time

I live in one, basically a 2.5×4.5m room with an en suit, kitchenette and its own small garden.

In front of house, granted retrospective planning as an annexe.

Cost of conversion was circa £15k but that will vary considerably depending on cost of labour in your area and ease of accessing services.