All wastewater pipes in the floor slab are incorrect.

Alright, the expert obviously has to be competent. Thinking along yourself (or having a woman who does that) is also never a bad idea. You might still notice a 90° twist yourself. But whether there is enough reinforcement inside or whether sealing was done properly later on, I wouldn't trust myself to judge. If you have enough money, you can also hire two experts for verification. Compared to the total costs, that's not much...

Thank you very much for your information. Since we received the site manager on the same day, I would never have thought that he would make such mistakes. I will now involve a lawyer, we - thank God - secured ourselves beforehand. Let's see what they say.. we are considering whether we even want to continue building with them... And regarding the facing bricks - we were presented with nice panels at the sampling appointment, where no word was said about the quality... if I had known that they only contain surface color, I would never have chosen them

Let's see what they say.. we are considering whether we want to continue building with them at all...

If you are aiming for a hefty penalty, you can of course seek to terminate the contract. If not, cool down. Everything is fixable. It'll be fine.

...
If not, cool down. Everything is fixable. It'll be fine.

Well, in my opinion, the wrong position of the wastewater pipes and the multi-utility entry cannot be corrected afterwards :confused:

Where is the core drilling supposed to go? Vertically down into the ground...? The wastewater pipes are usually sealed penetrations through the base slab and lead from beneath the slab to the outside. You can drill vertically, but to install a pipe horizontally under the slab with "non-90° bends"? I think that's hopeless. So tear down and rebuild, but surely no one does that voluntarily (definitely costs around 30K?)

But maybe a professional knows more than I have seen so far when producing base slabs.

How do you try to avoid such disasters? At least one of us was practically on the construction site every day before we even started. We dealt intensively with the subject matter of all trades, and hopefully, such "big issues" would have been noticed by us. Still, not everything goes smoothly with us either. Smaller things go wrong, but so far all have been fixable because they were noticed, communicated, and changed in time by professionals (site manager or one of the trades). I definitely do not rely purely on professionals anymore!

About the veneers:
I had the same case, the engobe is a weak point and only a certain amount per pallet may be damaged, only an expert can assess something like that.

My legal proceedings are still ongoing.

During the construction phase, our laser distance meter was constantly in use, also during the shell construction and finishing, positioning doors and windows and walls, accurate to the cm