Is KFW 40+ also possible with a decentralized ventilation system?

Whether allowed or not, I strongly advise you against getting yourself a decentralized ventilation system

To have all opinions represented here:

- Ventilation IS a mandatory component for Kfw 40+, as you yourself quoted
- The same quote says "ventilation system with heat recovery." So no restriction to central/decentral
- In the same document, there are further requirements for ventilation in the free text. Additionally, the technical FAQ applies to it.
- You need the KFW consultant anyway, ask him if the official documentation is not enough for you
- Decentralized is significantly cheaper but there are junk devices that cause trouble. Central is better. For residential construction, however, pearls before swine imho

I live in a two-family house, built in 2014, KfW 40, both residential units each have a decentralized ventilation system. So decentralized cannot be an exclusion criterion for KfW 40.

Regards