Hello,
we are building our house to KfW 40 plus standard. The general contractor says that a hot water circulation pump is not allowed, otherwise it would no longer meet KfW 40 plus requirements. However, when I check directly with KfW, for example in the sample "Confirmation for Application (BZA)," it literally states in point 2: "A domestic hot water circulation is permitted."
Does anyone have experience with KfW 40 plus and a circulation pump?
And one more question: By what latest point should the heating demand calculation be completed by the general contractor? And by when should the applications for KfW 40 plus be submitted by the general contractor? We have already submitted the building permit / planning permission application, and would now really like to proceed with financing, but there is still no information from the general contractor regarding KfW.
Thank you very much,
Jörg
we are building our house to KfW 40 plus standard. The general contractor says that a hot water circulation pump is not allowed, otherwise it would no longer meet KfW 40 plus requirements. However, when I check directly with KfW, for example in the sample "Confirmation for Application (BZA)," it literally states in point 2: "A domestic hot water circulation is permitted."
Does anyone have experience with KfW 40 plus and a circulation pump?
And one more question: By what latest point should the heating demand calculation be completed by the general contractor? And by when should the applications for KfW 40 plus be submitted by the general contractor? We have already submitted the building permit / planning permission application, and would now really like to proceed with financing, but there is still no information from the general contractor regarding KfW.
Thank you very much,
Jörg
The entire system is what matters. There is no general exclusion. What the general contractor (GC) says is based on their personal experience. Just like my architect believes that exterior wall insulation for KFW55 standard must be 20 cm (8 inches) thick. That is true if thermal bridges are not calculated but instead fixed allowances are used. It is the same with GCs. They commit to KFW40 standard without having done the calculations and already know that circulation pumps are disadvantageous. So, get rid of them.
I called the KfW directly, which is really typical German... So, a circulation pump is basically allowed, there just isn’t one that meets the requirements... Tip from my general contractor: pre-install everything necessary for the circulation pump and install it yourself later. That’s what we will do. Then nobody will care about it anymore.