Does the builder have to hand over the soil report?

Short answer to the question of whether the developer is obligated to hand over the soil report.

Yes, he is legally required to do so.

Why? Under a developer contract (Real Estate Agent and Developer Ordinance), according to the Building Code, it is classified as a consumer building contract. And in this case, a soil report is one of the documents that must be handed over.

What about if the developer did not prepare a report for the specific plot? Or would he have been obligated to do so as well?

How does it look if the BT has not created an expert report for the specific property? Or would he have been obliged to do so?

Sure, if there is no expert report, the BT cannot provide anything. There is no legal obligation to create one per se. Such an obligation exists only in exceptional cases.

You can see again how out of touch some people are with this... How am I supposed to prove to the contractor that he has an expert report to which I am entitled?

I don't know which fields you are working in... but if we have a document that we shouldn't have had to create and that can be used against us... then we would be crazy to give that to the customer, right?

Sure, you can speculate that the contractor is stupid enough to give it out. But a legal claim to it will hardly be enforceable if the contractor says "I don't have it."

And in this case it is also not productive. Soil is like a paella. I can poke it 10 times and not catch a shrimp... does that mean there are no shrimps in the paella?

And in this case it is also not productive. A bottom is like a paella. I can poke 10 times and not catch a shrimp... does that mean there are no shrimps in the paella?

If you poke 10 times and no shrimp sticks, then at least you know that it is a lousy paella... :-)

Above all, the restaurant owner does not have to disclose their recipe to me, even if I have bought and paid for the paella...

Where is the construction project roughly located? River nearby, hillside? Generally, only sand and gravel are "well permeable." In clayey soils, the fine-grained components lead to reduced permeability. As already mentioned, vegetation and soil organisms help to loosen the soil.