New construction according to the 2016 Energy Saving Ordinance no longer possible without a ventilation/exhaust system?

Hello forum,

I am completely new here. I hope you can help. It is about our new construction project, which is supposed to start in April. The goal is to build a KFW 55 house (solid construction). We actually wanted to realize the project without ventilation. Now we keep reading occasionally that for KfW 55 funding, ventilation is mandatory. Furthermore, today the municipal utilities pointed out to me that the Energy Saving Ordinance 2016 requires automatic ventilation. However, the house building company insists that it is not necessarily required. Can you contribute to clarifying this? 1. Is it really necessary? 2. Can you do well without it or should you invest the money? I hope for tips. Thank you very much

Energy Saving Ordinance 2016 does not require a ventilation system.

are you sure that you want to build without a ventilation system?

And for pure well-being, RegelAir in the windows is sufficient.

I was actually sure that I wanted to build without controlled residential ventilation. Unfortunately, doubts are gradually arising.

What is the reason that you want to build without controlled residential ventilation? Cost?