The skylight fogs up extremely and water runs along the edges

Jede Wette

I would bet against that. Where it condenses, there is no insulation or any sealing; that is located further inside.

Therefore, I would also suspect incorrect ventilation behavior. What kind of mechanical ventilation does the house have? If none is present, then you can blame the planner.

Measure the humidity sometime.

So if the condensation moisture primarily occurs at this location and, for example, not on the opposite side, I would first check for drafts here.

So the condensation moisture occurs on both the right and left sides. Almost at the same height.

I would therefore also suspect incorrect ventilation behavior. What kind of forced ventilation does the house have? If none, then you can pass the buck to the planner.

Hmm, well, we ventilate the entire apartment several times a day, so it really can’t be due to ventilation. Furthermore, in the apartment in the attic, decentralized fans with heat recovery are installed in the kitchen/living room and in the bedroom. The humidity is about 50%.

I have now done a test with a incense stick and couldn’t really detect anything :(
But I couldn’t see the smoke very well either, so I’ll have to do it again tomorrow in daylight.
Additionally, a colleague lent me a thermal imaging camera attachment for the smartphone, but that looks pretty okay so far? I think the cold bridges in the corners are normal, right?

Ok, nothing should happen at 50%. Then maybe something is wrong with the windows themselves. The images would only be meaningful with a legend.

Furthermore, a colleague gave me a thermal imaging camera to attach to my smartphone, but that also looks quite okay so far?

Unfortunately, he didn’t tell you how to use such a camera.

For meaningful images, the recording should be made shortly before sunrise at below 5°C, preferably below 0°C – from outside and inside, each time with a temperature color scale, but many of the attachable devices can’t do that at all.

The window is tight and in order. As I wrote from the beginning: the window-roof connection does not work as it should because it was botched there. What insights are further thermal imaging scans supposed to provide? The window is too cold, otherwise condensation would not occur there. Why is it too cold? Because there is a thermal bridge in the reveal and the entire window installation is probably improper.