Have the work contract checked by a professional

satisfied building expert?

But neither owner nor proprietor of the single-family house under construction, right? Rhineland greetings

But neither the possessor nor the owner of the single-family house under construction, right?

Rhenish greetings

Well, first of all, this is about the status of who is allowed to drive whom off the premises. That is the owner or the entitled possessor. The trade erected on the property always belongs to the owner of the property, since it is firmly connected to the property and thus an essential part of it.

It would be quite strange if the property owner were to disrupt the construction process (which happens often enough). For this reason, many contractors only build when they can (of course only in serious cases) keep any person off the property, and thus off the construction site. By transferring the "house right," the contractor is then also allowed to prevent third parties from entering.

However, I would be very interested in an explanation of the following quote:

If I grant the builder and the building expert access at any time, why does the developer still need house rights? If I, as the builder, delay the construction through improper actions, there are relevant paragraphs in the Building Code; house rights do not help you at all in this case.

If these sources are so relevant, then the reference to them should also be verifiable here. Where exactly can that be found? I do not know the term "improper actions" at all and cannot interpret it in that way.

And assuming you somehow get around § 280 I of the Building Code, who should then (legally permitted) decide whether the action (or omission) of the owner also meets the causality requirements and the breach of duty is present. It will certainly be interesting to see what comes next.

The discussion actually only shows why every builder is well advised to have a construction expert at their side.
Why are we even discussing this topic, there is already a ruling that declares the irrevocable transfer of the house right null and void.

"The clause constitutes a violation of § 309 No. 2 of the Building Code. If (as here, for example, in § 3 No. 5) installment payments are provided for, the builder must also have the opportunity to personally verify the contractual provision of the relevant construction status. Only in this way can he judge whether he has a right to withhold performance pursuant to § 320 of the Building Code. The restriction here is that the builder must request permission from the contractor. The contractor thus holds the key as to whether the builder can exercise this right."

Which brings us back to the topic.

If these sources are so relevant, then the reference to them should also be provable

What is this always nitpicking about....every claim for damages is a case on its own and must be treated as such. It is not for nothing that we employ highly paid lawyers here...

Voki - I'll just lean back and enjoy the afternoon coffee

Rhenish greetings

I agree with you. The coffee is great.

The trade erected on the property belongs at all times to the owner of the property, as it is firmly connected to the property and thus an essential part of it.

That is already clear to me; I should not have shortened it like that (once again) ops: Rhineland greetings

... there is already a ruling that declares the irrevocable transfer of the right of house null and void.

Which ruling is this about? Unfortunately, you failed to provide the source. Rhineland greetings