Luxhaus and competitors - diffusion-open wall

Water vapor. It should be able to escape from the wall to the outside (if present), but of course it should not be able to penetrate the wall from the outside inward. That is why there is a vapor retarder somewhere in the wall structure. In the past, foil was often used to make the wall diffusion-tight. Today, OSB is often glued at the joints, as it also stiffens the stud frame. How easily water vapor can penetrate a material depends on thickness and material and is indicated by the Sd value. Less than 0.5 is considered diffusion-open. 0.5 to 1500 is considered diffusion-retardant and over 1500 is considered diffusion-tight. OSB has an Sd value around 3 depending on the thickness, I believe.

...and how much amount of water vapor in g or ml per unit of time do you think diffuses through there? How long would it take, for example, to reduce the humidity from 60 to 50% after cooking or from 80% to 50% in the bathroom after showering?

Water vapor

How many % of the relative humidity can these "diffusion-open" components absorb/buffer? In what time scale do these exchange processes take place?

It is not about the water vapor that arises indoors. Ventilation, whether manual or mechanical, is responsible for that.

Not diffusion-open with ventilation makes EXTREMELY much more sense than diffusion-open without ventilation. At least one exhaust fan in the bathroom would definitely be a must for me.

Opinions can be so different. The bathroom is ventilated by airing out and that's it. Great if you have 2 windows and can create a draft. Add clay plaster and even a fogged, unheated mirror is clear again within minutes. Neither ventilation nor a fan is needed.
I don't like the whole ventilation thing because I can hardly imagine that they won’t eventually become breeding grounds for germs. Technology that I can well do without in my house.
Instinctively, I prefer the "diffusion-open building variant".
The ventilated curtain facade (larch in our case) is great.

It is not about the water vapor that arises inside the rooms. The ventilation, whether manual or mechanical, is responsible for that.

Aha, then which ones?