Hello,
Hello €uro, could you please explain it to me again in a way that I can follow )
Achieving KfW 55 is not quite easy (higher investment). For qp´´, an additional photovoltaic system is already required here.
Ht´ is the second hurdle to overcome. Experience shows that you achieve significant results when looking at the % distribution of the total loss. Usually, depending on the building construction, improvements can be made in AW, DA, AF (Fx=1). Possibly, for AW => 0.08 is already sufficient. However, that is no longer a "stone" either. Therefore I don't particularly like these monolithic AW.
Furthermore, thermal bridges. I suspect the flat-rate surcharge of 0.05. That means all thermal bridges according to DIN 4108 Bbl.2! Pay attention to the equivalence verification!
If it gets tight, a detail would also be possible. Thermal bridge verification is an option. However, this is expensive, so rather the rare exception.
Ultimately, construction supervision by an approved expert is required. That also costs. Overall, the subsidy is relatively quickly "used up."
Formally, with KfW 55 compared to the Energy Saving Ordinance standard, one naturally also saves heating energy. However, in reality only if the structural and system implementation corresponds to the superior planning.
At this point, one occasionally encounters various "miracles," so that the verification actually proves to be a "fancy calculation."
Subsidies usually cap the additional effort, but mostly do not compensate for it.
Best regards.