Humidity 60% Masonry damp

Outside air 5 degrees 80% rel. humidity = 5.44 g/m3 Indoor air 20 degrees 80% rel. humidity = 13.85 g/m3

Conclusion: Ventilation dries the room because more water is transported out of the room than comes in.

Ötzi was faster.

several times a day (5-10 times) shock or cross ventilation, get yourself a hygrometer with indoor/outdoor temperature and humidity with ventilation recommendation

Hm well, I can hardly do more than open the windows every day.

Yes you must. That’s just how it is with a new building. That’s why many who work recommend a ventilation system, as they don’t have the desire or time to ventilate for half an hour in the morning and evening. I believe the reason for this forum’s existence is the fact that nowadays you have to let the air out of the house. Meaning the moisture. Even at night, a person loses about 1 liter of water through sweat – that needs and must be removed. Kitchen steam comes on top.

Heating – Ventilating – Heating – Ventilating...

Actually, my question was whether it is possible that there is still so much moisture in the building that the air is so humid.

Ventilating or not

Yes, there is still well over a ton of water inside that will come out over time. If it is allowed to come out.

Yes, there can still be a lot of construction moisture
Remedy: ventilate more