Building defect cold bridge at the ring beam?

The construction-related weakness of monolithic walls are the concreted ceilings. For this there are ring anchor formworks with insulation layer (inside the formwork or from the outside). Was such used?

I googled a bit. Edge formworks for ceilings were used, which are equipped with tongue and groove at the front side (see picture below). My assumption is that with the formwork, which abuts at a right angle from the right, the tongue was not cut off and the gap was simply plastered over. Otherwise the second gap (arrow) cannot be explained. The first "gap" to the left of it is the groove, which is actually fine.

The thermal imaging camera showed no abnormalities from the outside.

That cannot be, a thermal transmission, as the name suggests, goes through.

Unfortunately, I did not take a picture of the corner from the inside, but in another room.

Then catch up on that.

However, there is only a cold bridge in the room described above.

That is not surprising so far, as you said that the ceiling does not exist in the other rooms.

My suspicion was that it is due to the insulation applied on the outside of the ring beam.

Yes, and I already said that the ring beam is positioned relatively low. It can hardly be wrapped thicker because with more insulation it would probably be too weakened. Your images also suggest that the insulation was only applied on the outside. That would be a mistake. In this case, applying it only on the inside might even have been the better approach.

I googled it once. Edge formwork panels with tongue and groove on the front side were used (see picture below). My suspicion is that with the formwork abutting from the right at a right angle, the tongue was not cut off and the gap was simply plastered over. Otherwise, the second gap (arrow) cannot be explained. The first "gap" to the left of it is the groove, which is actually fine.

Has the spot marked with the arrow remained an open gap that was merely plastered over according to your suspicion? To verify this, the only option in the end is to partially open the facade and check whether the gap was really "forgotten" to be closed. If that is the case, the cause can be quite easily fixed and the gap closed with insulation.

Yes, and as I already said, the ring beam is positioned relatively too low. It can hardly be wrapped thicker, as it would be too strongly weakened with more insulation. Your illustrations also suggest that the insulation was applied only on the outside. That would be a mistake. In this case, even insulation on the inside might have been the better way.

What do you mean by too low? You can't raise it higher, otherwise the house would become taller. I don't quite understand why the insulation of the ring beam should be applied on the inside? That is not common, see also here: [IMG width="484px"]https://www.sanier.de/wp-content/uploads/images/ringanker-Dämmung-grafik-us.jpg[/IMG]

Is the point marked with the arrow an open gap that was only plastered over according to your assumption? To check this, in the end, the only option is to partially open the facade and see if the gap was really "forgotten" to be closed. If that is the case, the cause can be fixed quite easily and the gap can be closed with insulation.

Yes, my assumption is that a gap remained that was only plastered over. At all other corners of the house, there is no gap visible there. That would also be my argument that the shell construction company should open it there and check or correct it.

What do you mean, too low? You can’t raise it any higher, otherwise the house would become taller. I don’t quite understand why the insulation of the ring beam should be installed on the inside?

I suspect means this problem: So too low in relation to the upper floor ceiling or its insulation. The floor ceiling insulation would need to connect at the height of, or better under, the ring beam if the ring beam itself is not insulated all around to form a completely closed thermal envelope. By the way, it’s quite similar in my case, only it doesn’t lead to such drastic thermal bridges for me. So more like this: Because U-blocks were used in my case and the insulation was placed inside the block and pushed further inward, the thermal bridge at that point is smaller. The correct way would probably be like this: Note that in the end the construction doesn’t matter; certain values must be met. For example, at 20°C indoor temperature and -5°C outside temperature, the temperature on the inside of the exterior wall must not fall below 12.6°C. An expert can calculate and verify this for you under other temperature conditions as well. If the thermal bridge at that point is too large, it is a defect; otherwise (probably) not. So the defect does not lie directly in the construction itself.