Garage roof neighbor above my insulation

Hello, the neighbor is renovating his garage roof. The garage is attached to my house wall. My wall above was insulated up to the (old) garage roof. Now it looks like he will make the roof higher than before, so that the wall end will be above the now created gap where his roof used to be. Apart from wondering whether he is even allowed to make the roof higher (even if it's only 10-20 cm), I am also wondering if the insulation gap (about 20 cm) that will arise will create a thermal bridge? However, it would then be located inside the garage. Unfortunately, I do not get along with my neighbor; otherwise, I would have already asked him what he intends to do. Thank you very much. Ed

Photos ?

Building permit? Sounds silly, but he needs it if the garage grows in height. You are allowed to replace/repair the insulation, just google "hammering rights," the neighbor has to let you onto his property for this purpose.

Possibly also take a look at the original building file to see how the attached garage is regulated. If he suddenly wants to attach it higher, you might be able to refuse that.

Best regards
Dirk Grafe

Thank you very much! I don't have a building file where something like that is described. So far, he has always built his huts and balconies etc. without a building permit, so I can't imagine it being different this time. Then there should also be a notice with a red dot hanging outside, right? But there is nothing hanging there. The garage is also being expanded on his side, making it wider. He definitely needs a permit for that. I just don't want to end up with some mold or water problem because he does the wall finishing incorrectly. Does anyone know the regulations for how it is supposed to look? I hate this kind of thing, I don't want any stress...

You do have access rights to the construction file, it is at the building authority.

Best regards
Dirk Grafe

Where is your insulation then located?

On your or his property?