Change of use permission?

[Panda2021]

Hi there, anyone have any experience of applying for a change of use of an external garage into a annex/ office?
Wondering how difficult this process Would be and if it’s something we should bother considering. Many help or advice appreciated.

We did this, although we knocked down our garage completely and rebuilt it (as a games room with mezzanine office). The issues we had were more to do with it being next to a listed building though - it did take us two years of pushing and eventually we got a planning consultant on board and got it through. We technically can't use it as a bedroom, although it does get used as an occasional guest room as there is a shower room so it works well for that.
We use it all the time so it was 100% worth it for us and saved moving costs!

@AlwaysLatte thanks a lot, it’s not a listen building nor near one so should be those issues,was just wondering in general is it a difficult thing to do/ hard to get permission before I start going down the rabbit hole of what if’s. Would like it as an extra space so don’t have to move in a few years/ ideal would like a sleeping area: toilet and we utility space for washing machine and space for deck!

Just doing this now - converting part of our attached (but not integral) garage to a hair salon for DH. Applied for change if use and building regs. We had problems with parking as apparently PP now requires 3 parking spaces and we’ve only 2 on our drive. After long discussion with local planning we’re actually proceeding under permitted development. The downside to this is that if neighbours complain about increase in traffic/parking then council investigate and we’d then be subject to enforcement and have to apply for full PP. During the conversion, we’re altering our drive to accommodate 3 cars and as DH will be the sole worker we dont envisage any parking issues.

Didn’t find the govt planning portal much help as the answer to one question meant we didn’t need PP but two paras under, the answer to another meant we did!