How much additional cost according to the structural engineer's calculation?

Whether luck ultimately fails because the customer wants to deviate from the standard procedure from plan A to plan Fis and/or because large providers with big legal departments know how to expertly and legally pull the wool over the eyes of laypeople, in the end it’s six of one, half a dozen of the other, right? If simple recipes are to be had, then I stick to the construction company "Maurersohn und Enkel" from the neighboring town as the one who most likely keeps its name clean with impeccable work.

You’re of course right there, but even in that case there are fraudsters or companies that go bankrupt. Everything has its advantages and disadvantages. For regional construction companies, I would definitely look for meaningful references. For us, for example, these were the regional banks and financing advisors. Everyone said that our general contractor does good work. The bank we ended up with therefore even came a little bit toward us with the interest rates. It is advisable in all cases to understand roughly what is going on and which measures are important.

And under no circumstances waive my right of special termination.

Then she can just go ahead and revoke the contract tomorrow.
This revocation period runs out after 14 days, then it is legally binding. If you waive it, you save yourself the 14 days of waiting. And that is absolutely common, because you don't just sign a contract worth 450,000 EUR for fun and games. At least I hope so.

Of course, you are right there, but there are also fraudsters or companies that go bankrupt. Everything has its pros and cons. With regional construction companies, I would definitely look for meaningful references.

Not only with regional ones, "too big to fail" is a widespread misconception. To counter the fear of bankruptcy risk, Big Names deliberately choose company shells founded in the imperial era ;-)

For us, these were for example the regional banks and financing advisors. Everyone said that our general contractor was doing good work. The bank we ended up with even gave us a bit of a break on the interest.

Yes, that is good. They know whose loan collateral is valuable and where there are disputes about the payout of retention security.

Understanding roughly what is happening and which measures are important is recommended in all cases.

Only that "wanting to be and remain a layman" is a main motive of those who go straight to the general contractor. That hardly goes together with needing to inform oneself.

That should then be for your bride search

The wedding has already taken place.

The wedding has already taken place.

Perhaps the right of withdrawal can still be exercised if the OP wishes.

I also consider this a definitely worthwhile option to consider. When I read such statements, it becomes a disaster waiting to happen. Every construction exceeds the calculated budget, and if 2000€ at the beginning are already unaffordable, it will become a problem later on.

Wir könnten nicht plötzlich 20000 euro mehr ausgeben. Wir haben vorgestern Erfahren, dass wir auch ne wanne für den Keller brauchen laut Bodengutachten- damit haben wir ebenfalls nicht gerechnet weil der Architekt meinte, Dainage reicht.....