Corner windows and sliding doors correctly installed - thermal bridges?

Do you have an infrared thermometer? I would measure directly in the corners with it. I was also surprised how dark the corners were on our thermal imaging camera, even though with monolithic Ytong you can't really go wrong. According to the expert, however, it is within the acceptable range.

Sorry, you really can’t see much in the pictures. Therefore, exact degree measurements haven’t reached me.

In the picture, the corner is measured at 9°C, the warmest point in the picture at 18.7°C, and the actual room temperature at about 20°C

Do you have an infrared thermometer?

Yes, I also have that on hand. Good suggestion to use it again and compare. But at least it is clearly noticeable that cold is coming from the corner, and the closer you get to the corner with your hand, the more you feel it. So it is definitely cold there.

I will measure again with IR, talk to the window installer, and now I already know the standard.

Is the window installer hired directly by you? If yes, you can basically try it that way first. However, a lot depends on what exactly was commissioned. For example, if you simply ordered windows according to the offer, it might not be a defect. Because then you ordered very specific windows with certain guaranteed properties. If you hired a developer or general contractor, they will not come out because they owe a construction that complies with standards. But then they are also your contact person. If you planned with an architect (at least up to service phase 5, better service phases 6-7), and he did not point out/pay attention to the fact that the elements need corresponding insulation properties, it would be a planning error. It would be best if you obtain an expert who measures this with calibrated devices (he can also accurately convert at other AT which surface temperature is allowed there) and advises you on how to proceed. The problem is that if these are really only window elements, it is not easy to add insulation afterward. Then most likely both elements have to be replaced and then plastered again, etc. Neither the contractor nor the window installer will want to do that. They will therefore resist and downplay everything. An expert helps here who can discuss on equal footing.

What did the BlowerDoorTest show back then? Otherwise, I think that many windows simply do not mean much wall, and a perceived cooler and indeed measurable radiation must be accepted where there is no insulation and metal/concrete is not insulated. By the way, I categorize something like that under the desired modern architectural style, which cannot necessarily be ideal in execution. The BU/architect makes the client happy, even though disadvantages arise. With an insulated corner, it would probably be less blue ;) Yesterday, the day before yesterday, or a few days ago, there was a thread complaining about an expansion joint.

Comfort will never be as high in the corner at really cold outside temperatures as it is by a wall. Even the most modern windows are still many times worse than a wall.

As for the rest, the post by hits the mark.

Was the window maker commissioned directly by you?

Exactly. We built with an acquaintance who is an architect. Formally commissioned were only the first service phases.

As I said, I will talk to the window maker first. He will certainly want to avoid a complete replacement or similar at any cost.

It was clear that the window and window corners compared to the masonry would be disadvantaged in terms of insulation and clearly disadvantaged from a thermal protection perspective, and that is also acceptable to us. What surprises me is that it is so distinctly perceivable and measurable.