Blower Door Test during construction not considered/What now?

Good day everyone,

I have a delicate problem. Or maybe none, that remains to be seen.

The new construction of my condominium (3 units) is nearing completion. Everything went well so far, but when it came to the fine details of the interior work, the problems started...

For example – vinyl flooring was installed and then they began with chiseling, drywall, tiling, and painting work. You can imagine how the construction dust and small stones affect the floor...

My biggest problem is, however, that we had the house built as a KfW 70 house. It is also stated as such in the construction description. But the developer seriously said that a blower door test is not necessary for measurement and proof for such a condominium. The bank thought differently.

After overhearing conversations among craftsmen, with dialogues like: "Do we now have to use this or that foam because of this blower door test," I am seriously concerned whether these considerations are being made too late.

What happens if the KfW 70 airtightness is not met? Do you have any suggestions on how I should proceed in this case?

What does the contract say? Did you buy KFW 70? If yes, the developer must keep making improvements until your bank is satisfied. Has a BDT been done? Or did they not have enough construction foam and then just left it?

The contract states KFW-70 compliant construction... I only caught the thing with the foam briefly. The BDT is supposedly going to be done in the next few weeks. However, no one wants to give me an appointment. I do want to be there and ask the inspection team questions etc. How long they can do corrections is questionable, the craftsmen apparently only do the bare minimum now and are paid irregularly. Presumably, there are financial difficulties behind this as well. Is it possible to manipulate such a BDT?

For the KfW, no BDT is mandatory! However, to my knowledge, something is calculated differently in the heat protection certificate.

The BDT is not necessary, but the leakage test is.
In my opinion, the BDT is only one way to carry out such a test.

In the execution regulations for the KFW program 153, something is mentioned about messtechnischem Nachweis?!

That is not entirely correct. As far as I know, the reference house according to the Energy Saving Ordinance is calculated as a tight house. More is stated in Paragraph 6, but only professionals understand that. If BDT, then better values ==> summary. We also achieve KfW 70 without BDT, of course, we also have other topics such as a ventilation concept.