Masonry quality of a concrete semi-detached house?

Hello! We are starting to deal with the topic "house purchase," specifically having an offer in mind, the "quality" of which we cannot yet assess due to lack of knowledge. It concerns a semi-detached house designed by a developer, and first and foremost about the walls. - Load-bearing walls: made of masonry from expanded clay, e.g., Liapor or Thermoton, d = 24 cm - Party walls: lime sand brick masonry or expanded clay solid block, d = 15 cm, with a sound insulation panel in between - Staircase walls: depending on static requirements, in lime sand brick or expanded clay solid block - Non-load-bearing interior walls: 10 cm solid gypsum masonry In particular, "Blähton" (not a typo) is unknown to me as a masonry material and cannot be assessed. If anyone would like to comment on "Blähton" and the other walls, I thank you in advance for your messages. Regards from Tom

Gargle up Liapor / expanded clay or enter it here in the search function, you will find a lot of information. Is it about stones or prefabricated element construction?

Hello! I am currently facing the same "problem" as the topic starter. We are also currently dealing with house construction and are considering a company that offers solid houses in prefabricated element construction. Here, the house is to be built with a 26 cm lightweight expanded clay aggregate wall, 14 cm of Styrofoam, and plaster. I have spoken to a home builder in my circle of acquaintances who said that if you build, then use a 36 cm Ytong wall with clinker. Surely that is probably the best but not affordable for everyone. Now my question... Are the walls I described first completely unusable or is that simply a modern construction method where such a thick masonry is no longer necessary? I have also heard that Styrofoam promotes condensation from the outside, which sooner or later results in mold. Is there any truth to that? Thank you very much for your answers in advance.