New window between frame and wall very cold. What to do?

But it is true that foam can also be RAL compliant and that you should preferably let a craftsman do what he is experienced at (as long as it is technically OK).

Unfortunately, what is really true (not in the sense of "correct," but "really") is that nonchalance when measuring (or ordering the windows according to plan dimensions right away) is often and gladly overfoamed as well.

Minimum thermal protection according to DIN4108-2 is not met. 89mm hollow bricks probably do not provide the thermal resistance to make the passage across the profile width of the window difficult enough to achieve the minimum temperature of 12.6°C at NAT. If the window is airtight, that will be the problem. A relatively easy remedy here is an interior reveal insulation made of calcium silicate or wood fiber insulation boards (I would prefer the latter). The windowsill remains a problem, but that is how it is.

Alternatively from the outside, but it only makes sense with ETICS and that is actually not necessary with 89mm hollow bricks in 30mm thickness.