Ventilation in windowless rooms

Hello,

we have just built a Kfw70 prefabricated house. We do not have controlled residential ventilation, but ventilation was planned for all windowless rooms. This goes through the roof for interior rooms, and through the wall for the pantry.

In a small WC we have a fan (as you would expect), but the ventilation in the other rooms is simply a pipe going to the roof. In the pantry it is even just a roughly 10 cm hole in the wall, on which a plastic cap is supposed to be placed on both sides.

Is this normal? What use is the best insulation if we then have holes in the wall and to the roof? And doesn't that give underground values in the blower door test?

What use is a new building with obviously so many rooms without windows? Something obviously went wrong with the planning of the floor plan.

Why many? We have a pantry, a small WC, and in the [Einliegerwohnung] another storage room.

Could it be that this is the venting of the water pipes and not a room ventilation?

No. The plans clearly state room ventilation. As I said, in the pantry there is simply a roughly 10 cm hole in the wall where a plastic exhaust vent will be installed.

Good evening,

In a small WC we have a fan (just as you would imagine)

Who sells/installs something like that?

Rhenish greetings