Plastering work in new construction was poorly done, any experiences?

Due to the following information

I "actually" only see the possibility that you perhaps let them do rework against another payment in an amount yet to be negotiated (--> compromise). Because the company seems basically capable of plastering well if some rooms are fine.

Were it always the same employees or were the last rooms perhaps plastered by trainees? I ask because you might then be able to use that as an argument.

A compromise would really be a solution, but the company says there is no possibility for rework. Everyone always looks quite helplessly at the wall.

It was always the same plasterers. But I must also say they plastered our detached house for 2.5 months. The entire house construction took almost three years. The construction company simply didn’t work at all for 5 months.

From the front means from in front of the wall. So at a right angle to the wall being viewed. Grazing light skims past the wall. So the light from the window is actually only allowed to illuminate the wall behind the photographer.

Only Q 2 was agreed upon, but it is simply noticeable that the unevenness is especially in the most recently plastered rooms, even the basement rooms are plastered more nicely

The comparison does not matter at all. It may be that the experienced journeyman plastered the basement, and someone else plastered upstairs, but what matters is only the statement that Q2 must be sufficient for a textured wallpaper.

Of course, something can be done about it. The painter can fill and sand. But it comes at a price.

It would be quite labor-intensive to smooth that out, especially because there are certainly some areas where you'd only get access with scaffolding/platforms. But it's definitely doable, the painter would have to do it – my idea would also be to apply a generous amount of filler again. It’s not so nice in an occupied state, because of the sanding dust and because you might have to clear out or at least move and cover some things. Whether it’s worth the effort for you, you have to decide yourself. I would probably overlook it and plan for it if it’s inexpensive.

Yes, it is partly really wavy. The mirror in the bathroom stands about one centimeter away from the wall due to the unevenness.

But you measure something like that with a straightedge. Can you take some photos with it? And why has it only become noticeable now, didn’t you check that after the interior plastering?