We want to build, is what is being offered to us okay?

In the north there are many providers, be it Viebrockhaus, Elma or all those we have spoken with. This does not mean that it is DIN-compliant (according to 1053) but at least common practice.

An article states:

"Core insulation in cavity walls In fact, there are also approval certificates from the Institute for Building Technology, Berlin, for certain thermal insulations (e.g. mineral fiber insulation boards), according to which these may be used as core insulation to completely fill the cavity of cavity walls for exterior walls. According to the approval certificates, the insulation materials may be used as a thermal insulation layer for cavity walls with an air gap according to DIN 1053 part 1, edition November 1974, section 5.2.1. Contrary to section 5.2.1 of this standard, the insulation materials may be installed without a continuous air gap. The Institute for Building Technology, Berlin, grants a general building supervisory/building law approval for the corresponding construction type with the certificate" (Source: Lawyer Erich J. Groß and Construction Engineer Dieter Riensberg, Kiel: reprinted in BauR 1986, p. 533 ff)

The article also states that the construction still violates DIN 1053. If you are really interested, read the article – it is very insightful (even though it is already 30 years old).

Hmm. I wonder if I can ask the provider to still leave an air layer between the doorbell and the insulation? Would that involve additional costs? You only need a few more bricks, right? Because even if he says that the insulating material is approved to be installed without an air layer, it doesn't hurt to have one, does it, or maybe it does?

The problem will then be the wall anchors – they are only approved up to a certain shell distance. Beyond that, there are special anchors, which depending on the situation will already be considerably more expensive. The question is also whether the masons of your BU even still know how to build ventilated facades (no idea if that is an absurd thought). Doesn’t hurt – however costs beyond the wall anchors: 4 cm on each side for a 10 m x 10 m house at 100 € / m² will cost you 160 € in land – well, that’s manageable.

Aluminum reacts in an alkaline environment. This forms gaseous hydrogen, which creates the pores in the mass and escapes without residue.

Therefore, no one has to be afraid of aerated concrete, because after the manufacturing process is complete, this propellant is not present anymore.

The volatility certainly refers to the hydrogen. The hydrogen bubbles formed in this reaction are responsible for the pores. I rather do not believe that aluminum "disappears" (is volatile) in this process. Nevertheless, I am convinced that aluminum (no matter the amount) in the wall of a house does not pose a danger to the residents.