A rough idea of costs/work to convert a garage to studio/apartment?

[d000hg]

Our house has a rather lovely single garage, which was originally a coach-house (it was the mine-manager's house in the coal-mining days ~1880). It's a brick-built garage with concrete floor (including inspection pit) and decent slate roof, including a chimney. Internally it's actually two rooms, a largish single garage and a tiny room separated with a wall which has the fireplace in, so the chimney & dividing wall are 1/4 of the way along the building. At the far end are large wooden double-doors, at the near end is a normal door to access the small room. There are two small windows only, one in each 'room', though there clearly used to be another entrance which has been bricked up.

Anyway, I've always thought this building is too nice to waste as a garage we don't use except to store tools. My thoughts are that it could be wonderful as:

1. A home office - I work from home
2. A dedicated studio for my personal music interests
3. A little 1-bed cosy apartment, that we could rent as a holiday let/air BnB

I could imagine the double doors (which open directly opposite the woodland surrounding our property) could be replaced with glass and the fireplace could be retained, giving a single main room + small bathroom & kitchenette at the far end. That would allow it to be used for any of these purposes... or I could tailor it more specifically e.g. no bathroom/kitchen for a studio, maybe kitchen in the main open-plan room for a holiday cottage. It doesn't have water/drainage currently.

I would love to hear any ideas on what this might cost if I didn't do it myself, and a very rough summary of major jobs it would entail. And what I would have to do in terms of building regs... I imagine this might vary depending on intended use? I definitely don't want it to be a separate property e.g. for long-term lets, not sure if that makes a big difference.

I see it's a bit cheeky to ask for all this so a very short summary is just fine. I rather imagine it would be a case of gutting the inside, damp-proofing and then fitting out. An internal wall would help insulation but I don't know if this (and roof insulation) would have to be up to current spec for these uses... it would lose some valuable internal space.

Thanks in advance.

 

[d000hg]

(if you want photos/measurements let me know)

 

[Tigercubrider]

a mate converted his detached garage with no planning issues into a home studio.
It looks like a normal garage as he retained the doors although the "garage" is 4 feet deep.

Once you have a habitable structure, then all sorts of planning issues come into force.
I'd go the Granny Flat option first, only if you want to use it as sleeping accommodation.

They may set restrictions to prevent rental or splitting the property later.

My G/f lived for years in a granny flat above a stable and i am 99% certain that it was done on the QT in the 80's and din't technically exist.

I will see my mate later and ask him the cost. We all helped labour wise so it was just timber, rock wool and plasterboard, plus electrics.
The only pro was the plasterer who skimmed it.

Once you start paying trades it will escalate, but they will be quicker.

any toilets will cost