House manufacturer threatens to stop work

Going to a lawyer often sounds like "let him enforce that for you." That is a different task, which I recommend handling sparingly.

I am already involved in my second legal case regarding house purchase and house construction, and from my experience I can say that no lawyer has so far held back their client. Why would they? They still get their money anyway?

I can’t otherwise explain why in case 1 the lawyer did not explain to his client (opposing party) that what she was doing could become really expensive (in the end 100K), or why the lawyer of party 2 in the next case did not explain to his client that it would be better to waive suing for the outstanding invoice because it will now cost him a lot of money instead of getting money.

It was also completely ignored that it always takes two parties. What use is it to me if one party is skilled in nonviolent communication, but the other party just hits out, is sure they know everything (because after all they have already built 100 houses and you haven’t)?

Exactly. If you go to a lawyer with the working hypothesis "the other party is stupid" and the mandate "so beat them with legal briefs," a good lawyer will always respond with "Counterproposal: I will get the best outcome for you." You achieve better results through "when in doubt, favor the client but without losing sight of the goal" instead of "waging war on the most confrontational collision course possible." A good lawyer does not stand in the way of their client’s realization that they might not (alone) be right.

It's about a mere €1,600, and I will lose those things too, but in return I will sue him for poor performance and claim damages amounting to €129,000, from which he can then deduct the €1,600.

And with the "poor performance lawsuit" with an uncertain outcome, the next lawyer earns as well? You really want to know.