New building KfW55 with gas, solar, and controlled residential ventilation with heat recovery

What I don’t understand and please don’t take it the wrong way, I am still at the beginning, every construction company, whether solid or prefabricated house, every architect and planner I have spoken to told me that KfW55 can only be achieved if the correct thermal conductivity of the materials is given AND the technology fits.

In terms of technology, for gas this means the condensing boiler AND solar thermal AND controlled residential ventilation with heat recovery. This information was given to me from different sources, which I have come to terms with.

Has your energy consultant calculated such a good primary energy demand that KfW55 is actually possible without the three technical components?

Our appointment with the energy consultant is supposed to take place soon, maybe I will be wiser then

Hi XeNiA, since we are entering the final phase with our general contractor after purchasing the plot, I would also be very interested in details of your planning. Although we have not yet had an appointment with the energy consultant, the sales representative of our general contractor said after consulting with the energy consultant that compared to the usual gas+solar combination, an additional solar module would be necessary. : Are you already further along with this topic?