Does a KFW70 house become a KFW55 house this way?

But the energy planner will have done that.

Yes, he calculated that. But even without achieving KFW 55, we would install a small photovoltaic system on the roof because it pays off through self-consumption (and I believe even much more in the future).

Hello Nordlichten and nordanney,

what is your wall construction and what U-value results from it?