KfW 40 plus - Circulation pump allowed?

The entire system decides. There is no blanket exclusion. What the GU says is his personal experience. Just as my architect thinks the external wall insulation for KFW55 has to be 20m thick. That is also true if you do not calculate the thermal bridges but are content with the flat rates. It's no different with GUs. They owe you KFW40 without having already calculated and know that circulation pumps are unfavorable. So get rid of them.

I called the KfW directly, that's really so typically German.... So, a circulation pump is basically allowed, there just isn't one that would meet the requirements.... Tip from my general contractor, pre-install everything necessary for the circulation pump and install it later yourself. That's how we'll do it too. No one will care about it anymore.