Exterior walls built with a 4cm tilt

Your quote referred solely to the statements that a demolition is inevitable and, to put it bluntly, the lawyer should already prepare the complaint

That was not mentioned: I consider the alternative "demolition" to be so highly probable that those making the statements urgently need to be informed that this may have to happen. In case of defect complaints, one can make formal errors, therefore I consider legal advice to be sensible when drafting.

Otherwise, the bricklayer can later take the position: well, I will rebuild the wall at my own expense - but I am not responsible for what others have built on top of it. And legally, a simple "hey, you, bricklayer, I don't feel safe about this, whether it will work out well" is not a defect complaint. Not even stated in the presence of witnesses.

Our shell builder built an exterior wall slanted by about 4 cm (from bottom to top).

Show a photo ...

We need to initiate the conversation tomorrow.

Better write a complaint about defects, but formally correct. So get advice ...

If I (layperson!) understand the DIN correctly, 8 mm deviation would be acceptable; but you measured 40 mm. Not good.

before running to a lawyer and incurring costs, you can first have the conversation. there are also site managers/companies who gladly want to get rid of their botched work. tips on how to fix it again (support the ceiling and then rebuild the wall) were given and are not a big deal for the company. at the same time, throw the arguments about more botched work (windows...) into the mix and see what happens.

if the site manager still does not comply with the request to remove the botched work, you can always run to a lawyer for the notice of defects.

Short info about the matter: The wall is actually being renewed. In the end, everything was quite relaxed, without pressure/threats. The only thing I found unfortunate was that the site manager didn't take it seriously at first. Arguments like more botched work especially towards the window wouldn't have worked, since this is a terraced house construction and no window is installed in this wall.

before running to a lawyer and causing costs, you can first have the conversation.

Lawyers are not people-beaters. It’s precisely about not causing costs by letting other contractors continue under the false belief that the trades before them provided a solid foundation. Pulling the emergency brake too late can get expensive.

Involving a lawyer doesn’t escalate anything, not even atmospherically – they don’t even have to appear, just advise when drafting the complaint. That’s a formality so the client can say: I gave timely notice that, in my opinion, a defect exists. C’est tout – no one is harmed.

P.S.: looks like our writing times just crossed ...

Arguments like more botched work especially around the window wouldn’t have worked here, since this is row house construction and there is no window built into this wall

Does that mean you would have effectively let your house “collapse” about 4 cm into the neighbor’s property (or vice versa)?

before rushing to a lawyer and incurring costs, you can first have the conversation

Yes, of course, but in the first post it said, "the cleaner will make up for it." Therefore, you have to expect the worst. A good general contractor would have said on their own, "We'll do it again."

The problem is that formal errors can become expensive.