Ventilation through wall or ceiling outlets?

Between 2 heated rooms there is no vapor barrier, and certainly not between 2. What does the ceiling/roof structure look like?

The pipes for the controlled residential ventilation are installed under the ceiling. This takes about 12 cm of height in the living rooms, but we have added one more stone, so we still reach 2.69 m. Here are a few pictures (the green pipes coming out of the ceiling).

One more question. Is it really a property developer or a construction company?

Thank you for the information!

: The ceiling between the upper floor and the attic is a collar beam ceiling. The thickness is indicated as 24 cm in the section drawing. The attic is heated and the roof forms the thermal envelope.

: We are building with a developer.

: We are building with a developer.

Sure? Normally, the developer builds independently of you and you simply buy the house. This results in real estate transfer tax being due on both the land AND the house. Changes/adjustments are very difficult to enforce or not possible at all.

That's right, you are correct. It is a general contractor. We already had the [Grundstück] and we have commissioned a company with the planning and the house construction.