KFW - fulfilled by which measures?

Well, exactly this effort. As far as our architect has told us, it is only necessary if you want to sell a house or have something to do with KfW, right?

There is no checklist where you go through and afterwards know whether KFW 55 or not. A calculation must take place for this.

There is no checklist to go through and then know whether it is KFW 55 or not. A calculation must be carried out for this.

That is clear to me, I just want to know whether KfW is within reach with the planned construction method or not and whether the effort with the energy consultant,... is worthwhile.

As already written. Only an energy consultant can calculate that for you. You then have to commission and pay for it.

Just take a look at the documentation of program 153 regarding the reference value method. Then you have a very good point of reference without having to calculate anything.