Solid wood parquet on underfloor heating

If I wanted to know this exactly, I would ask for the thermal resistance, which by the way was actually requested by Lieblingsheinz as a lambda value, and we had also used this in advance for decision-making.

Does that mean Heinz von Heiden (with whom I am also building) "coerced" you into providing the value for the heating load calculation? I'm surprised, because they usually don't want to give the builders any plans besides the building application plans, basically..."You won't get anything" and so on.

I am surprised, because apart from the building application plans, they basically don't want to give the builder any plans..."They won't get anything" etc.

Keyword consumer construction contract = legal OBLIGATION to hand over all necessary documents. This is not a point for discussion.

Unfortunately, only those plans are "necessary" that are required "to provide proof to authorities that the construction complies with public law regulations." -> For example, these are not even detailed plans of the electrical installation. The original wording says: "The electrician does not make plans. Go to the construction site and take photos." So you also don't get plans showing exactly where the water pipes of the underfloor heating run, etc. But that's another topic. I don't want to distract from the main topic of the thread any further.

For us, it was such that when we were still planning on our own, we also determined the floor coverings, and in doing so, I considered the thermal transmittance value, the density, etc. We have bare glued oak planks on the floor, about half the house. The heating planner from Heinz von Heiden called at some point, they needed the lambda value, at first I didn’t even know what that was supposed to be. I had already provided the thermal transmittance value there well in advance as a precaution. For the electrical work, we have a photo book; for the loops of the underfloor heating at least a usable photo documentation, but sometimes something was built over before we could document it. I can only recommend documenting. For us, it was also said about many things that there were no exact plans. Many greetings Gabriele

Unfortunately, only those plans are "necessary" that are required "to prove to the authorities that the construction complies with public law regulations."

That is not entirely correct. All plans that may later be needed for maintenance and repairs must be handed over. This includes electrical planning as well as heating planning and design. These documents rather come from the case law regarding consumer construction contracts, but are definitely performance-related proofs that must be handed over.