Cold roof - Are roof windows necessary for cross ventilation?

Then ventilation must be provided there. And it remains a warm roof...

Is there a standard for that? Are windows allowed there? I don’t really see myself ventilating there daily in winter.

Certainly not according to the standard - and since you are not often up there, windows are pointless - better make core drillings on the gable sides and let it flow through there.

Or you observe it first - the attic is not plastered and sealed for you either, so there is already an air flow per se.

I will set up a data logger with temperature and humidity sensors up there and observe.

Okay, thanks for the tip - I guess I'll do that too. Exactly - nothing is plastered.

We do have a ventilated ridge, the BU said.

Shouldn't the moisture be able to escape through the wood fiber boards/roof insulation and the vapor-permeable underlay?