Construction company wanted in the Stuttgart metropolitan area!

You have already made up your mind anyway... you list the above under "+" even though you yourself say that you have no idea or there are no values, with the competitor you list values like db as a disadvantage even though no comparison with Hauser is possible... why? What do you want to achieve with that? I therefore refer to the first sentence: you have long since decided, no matter what you say now

The statement in the construction performance description is simply that the sound insulation should be very high due to the high raw weight. "Very high" is now a very general and non-comparable statement. Unfortunately, Hauser itself does not provide any values (db figures, U-value, etc.). I listed it under + because I believe I read somewhere that Liapor walls have a bulk density of 1,200 kg/m³ and the Ytong stone somewhere around 350 kg/m³. Higher bulk density = higher sound insulation, or am I wrong?

Please don't misunderstand, I really haven't decided yet. I like both companies, both have advantages and disadvantages, and both are similarly priced. I'm just trying to compare the two building materials/concepts here with partly incomplete information.

The bulk density is pretty much irrelevant beyond a certain point! It really depends on the windows, didn’t you look at the table? Here is another similar table for brick walls, but it is similar for all building materials: if the windows only have a sound insulation of 32 dB (like the standard ones), it doesn’t matter how much sound insulation the rest of the wall has, you will never exceed the limit set by the window values. For Liapor, we’re also talking about a maximum of 49-52 dB as a pure sound insulation measure. What this means is shown in the table:

I know aerated concrete from several of my father’s previous apartments - one of them even on a main road - and from my "company apartment" in the factory building, each with flawless sleep, and therefore I cannot comprehend the usual soundproofing horror stories in the slightest. You will be able to drill easily in Liapor, and for fastenings through ETICS there is now a wide range of products available. A ceiling suspended because of electrical cables, on the other hand, sounds to me very much like a construction error; it can certainly be solved more cleverly. Have you ever asked Dennert how they handle it there (their stone wall part would be similar)?

Higher density = better sound insulation, or am I wrong?

The equation is simplistic physics. Stiffness works well against vibrations "immunization," yes - but it cannot only be achieved through mass. So the argument is "correct," but still not suitable as a counterargument regarding other materials. Many students have settled for a "D" in physics because advertising claims must sometimes be simplified to the limit of pain.

The bulk density becomes pretty much irrelevant beyond a certain point! It really depends on the windows, didn't you look at the table? Here's a similar table again, for brick walls, but it's similar for all building materials: if the windows only have a sound insulation of 32 dB (like the standard), it doesn't matter how much sound insulation the rest of the wall has, you will never surpass the limit imposed by the window values. For Liapor, we're also talking about a maximum of 49-52 dB as a pure sound insulation measure. What this means is shown in the table:

I only saw your answer afterward and looked at the table. So the sound value is actually completely irrelevant. Because in the exterior wall I have the windows, which are significantly worse, and in the interior wall I have the doors, which are probably also significantly worse. Alright, then that topic is off the table.

A suspended ceiling due to electrical cables, on the other hand, sounds to me very much like a design flaw; there must be a smarter way to solve that. Have you ever asked Dennert how they handle this (since they would have a similar situation with the stone wall part)?

Hauser's statement is that all necessary things for the floor (underfloor heating, etc.) go into the floor and the electrical system (lamp connections, etc.) goes into the suspended ceiling. This way you have a lower floor construction and the suspended ceiling would be an advantage because you could still make changes later.

I just checked again: Floor: 40mm thermal insulation + 20mm underfloor heating stapler board + 60mm calcium sulfate flowing screed Ceiling: I think I read somewhere 12-13cm

I did not ask Dennert about this because they were not on the list or we had no contact.

According to the website, Dennert has a 20cm hollow core slab ceiling and apparently installs all the pipes there. I currently cannot tell you why Hauser does it completely differently.

Hauser: "Reinforced concrete hollow core slab (with heat-insulating polystyrene core) according to static requirements as a solid ceiling slab"
Köhler: 22cm reinforced concrete ceiling