BlowerDoor test mandatory for ventilation system and KfW70

Is the BDT not mandatory for KFW houses anyway?

This has already been mentioned several times above: yes, if you use the funding.

No, it is only mentioned once in #4, otherwise there is always a connection to [Kontrollierte-Wohnraumlüftungen] - that is why I asked again.

Sure? I thought a BlowerDoorTest is only required if a ventilation system or a prescribed air exchange rate must be met? As far as I remember, our energy consultant did not say that we are automatically obliged with the KfW70 program... It probably depends on the exact calculation.

Sure? I thought a BlowerDoorTest is only required if a ventilation system or a prescribed air exchange rate must be maintained?

If you apply for funding through the KfW bank, you also have to prove the energetic implementation of the standard 70, 55, 40, 40+ or PH. In my opinion, a Blower Door Test is indispensable for this. In any case, we do not manage any construction project where this test has not been carried out. Rhenish regards

We built KFW70 without subsidies. The BDT is standard with our in-house company anyway. It should generally be done because it reveals related defects in construction. And, for example, it is a good feeling to have a building envelope at passive house level (regarding airtightness)...