Is retroactive approval possible for an extension over the garage?

Hello,

in the house we purchased, the previous owners converted the existing and approved garage roof structure about 30 years ago into a small granny flat for one of the then teenage children. There is a bed, a kitchenette, and a small bathroom - the whole thing is not approved. There is also a dormer, which is probably not approved either (does it have to be?)
The garage adjoins directly to the neighbor's garage and is therefore a boundary building.

[*
Are there chances for retrospective approval (NRW, no development plan)
[LIST]
[*]as it is
[*]as a hobby room after dismantling the bathroom and kitchenette


[*]If not:


[*]Could it be reported by neighbors at any time?
[*]If yes:
[LIST]
[*]Does it make a difference whether the room is used or the access is sealed off?
[*]Would one possibly have to pay a fine or "just" dismantle it?


[*]If one applies for funding for energy renovations, is there a risk that someone has to report this conversion?
[*]How does it look in terms of insurance if the house burns down, for example... could the insurance refuse payment?

[/LIST]

Can anyone assess this here? And if not, who could advise us on this?

Thank you very much for your feedback

Wedding dress remains wedding dress and red cabbage remains red cabbage - the same applies to an illegal construction. This is not about kindly asking once more if one might be allowed to watch TV for an extra hour.

Keep a low profile and don't wake sleeping dogs. Be happy about the extra space and that's it.

A wedding dress remains a wedding dress and red cabbage remains red cabbage - that also applies to an illegal building. This is not about asking very nicely once more if one might possibly be allowed to watch TV for an hour longer.

Well, I would find it interesting if one could get approval for it as a non-living space after dismantling... then it's simply no longer a wedding dress.

Keep it low-key and don’t wake sleeping dogs. Be happy about the extra space and that’s that.

I just worry that in case of fire (unlikely, but the consequences severe) there could be problems with the insurance - not to mention nosy neighbors tattling if there is a dispute over trivial matters...

I'm just worried that in case of fire (unlikely, but consequences extreme) there could be problems with the insurance – not to mention snitching neighbors if there is a dispute over trivial matters...

Then the alternative remains the deconstruction. Is that the option you want to hear?

If you look at it that way, the desired answer would probably be that a conversion into a hobby room is approvable and the space can thus be saved.