ᐅ Are Cold Corners Still Acceptable in New Construction Today?

Good evening,

From a physical standpoint, the corners of an exterior wall inside a room are always colder than the other walls due to the larger exterior surface area relative to the interior surface.

In my rental apartment, the difference on cold days (outside temperature -10°C (14°F)) is about 5 to 6 degrees. Unfortunately, mold always forms there as well.

Is it possible to address this issue better in new builds (solid construction house with 36cm (14 inches) aerated concrete walls)? Does anyone have experience or guidelines on how large the temperature difference should or can be?

Thank you in advance for your advice!

It is rumored that in a newly built house constructed according to recognized industry standards, cold spots and mold are not an issue.

Does that mean there are no longer any temperature differences? Or does building according to recognized standards of good practice only ensure that mold no longer forms in the cold corners?

I have to admit that I didn’t take measurements, but I would say that, if there are any temperature differences at all, they are probably very minor. Doesn’t the construction method also play a role here? With a cavity wall, there shouldn’t really be any differences. In the case of a solid wall, the ceiling needs to be installed with insulation strips, or how does that work? It’s actually an interesting question — also when it comes to lintels.

I just read about the FRSI factor in DIN 4108. It allows calculating at which temperature differences there is a risk of mold. However, there is also some criticism of this method.

In a new build, there should be no problem with normal humidity levels if everything is done correctly. You can't eliminate it entirely, but here the difference is about 1 degree.
If necessary, you can build round, so there are no external corners anymore.