Large impact joints in the shell construction still within acceptance or defect?

That should actually work. The house is being built according to the [Energieeinsparverordnung 2016].

But here I am talking about soundproofing ... As far as I know, unfilled bricks are not allowed in multi-story residential buildings ... Therefore the question: does a REH fall under a multi-family house or is it comparable to a semi-detached house where you can do whatever you want... I think rather the latter ....

But I am talking about soundproofing here...
As far as I know, unfilled bricks are not allowed in multi-storey residential buildings...
So my question is: does a REH count as a multi-family house or is it comparable to a semi-detached house where you can do whatever you want... I rather think the latter...

It is the latter. It counts like a semi-detached house.
However, the partition wall is (theoretically) constructed on each side with 17.5 cm sandstone + 5 cm mineral fiber board. If this had been done properly, it should actually provide quite decent soundproofing.

Let me give you a hug ... real crap ...

- Masonry is done with 36.5cm Poroton bricks

May I ask what has become of your house? Are you satisfied with the thermal insulation, or do you have cold bridges at points where the joints are too large?