Delays with the general contractor, no deadline set according to § 650 Building Code

Already started. However, there is currently also a criminal complaint against the general contractor. But that is another matter...

Sounds familiar to me somehow. You probably didn't try to get the services at the agreed lump sum price?

You probably didn’t try to get the services at the agreed flat rate?

No. That would have only been possible through the courts. And then I would have had court costs, but a bankrupt general contractor. Sometimes it doesn’t help to be in the right.

Now I have presumably discovered the relevant passage after all:
"After the delivery prerequisites have been met, the completion of the ***-house services
for an almost turnkey house is at most 10 months
for a turnkey house at most 11 months." That was stated in the fine print of the 20-page offer.
At another point in the contract it says, "Agreed delivery dates only apply if contractual and technical order clarity exists and the delivery prerequisites (building permit, completed sampling, release of work planning, overall financing confirmation, irrevocable guarantee for the final payment, timely defect-free completion of the basement or floor slab in case of client-side construction, refilled construction pit etc.) are met and present for the ***-house."
That would mean that the delivery prerequisite only applies once the basement is already built and the construction pit has been closed and from then on only 10 or 11 months. Oh man, I really laid a big egg for myself there.
But it also can’t be that the general contractor has no time pressure until then and can let things drag on.

I couldn’t find anything about withdrawal, but it’s not that simple. Every new general contractor would demand planning costs again, prices today are certainly at least 10% higher than at contract signing at the end of 2019, the old general contractor will retain part and other prefab house providers are partly booked out until next year. In 10 months there will still be interest on the standby loan since the credit is already running, etc.

I would be more upset about my own stupidity if I hadn’t managed to get the deputy managing director on the line through several contacts today. He apologized, said this is not their normal way of working, and tomorrow, when the responsible sampler is in the company, he wants to talk to him about it. Let’s see what happens. I’m feeling somewhat hopeful again. But this is not the first time...

Now I have probably discovered the relevant passage after all: "After the delivery conditions have been met, the completion of the ***-house services for an almost turnkey house is at most 10 months; for a turnkey house at most 11 months." This was stated in the fine print part of the 20-page offer. Elsewhere in the contract it then says: "Agreed delivery dates only apply if contractual and technical clarity of the order exists and the delivery conditions (building permit, completed sample selection, approval of the work planning,

You write: ...,,,, part of the 20-page offer. What is important is what is stated in the contract.

I believe I read that if nothing is stated in the contract, the times that were discussed or recorded in advance apply.

The regulation on the completion date according to § 650k para. 3 of the Building Code is also to be applied analogously and is decisive for the construction contract. If a binding date cannot be determined or is not included in the contract, the information in the pre-contractual construction description applies. If nothing has been specified there either, the developer is obliged to commence the construction work promptly and to complete it without delay.