> I think modern domestic houses its the opposite. At least in Netherlands insulation is such a strong focus, due to climate change I think, that modern appartments have terrible ventilation

The link I pointed to is all about ventilation, so just because people ignored an important component of building science, and focused on one aspect, does not invalidate it.

And while climate change is important and using efficiency to deal with it is useful, the thermal control layer is actually the least important of the four:

* https://buildingscience.com/documents/insights/bsi-001-the-p...

'Bulk' water (precipitation) and moisture can cause deterioration of the building materials (rot, crumbling), and also mold, which has its own health effects. Leaky houses can often blow conditioned air at much faster rates than thermal leakage.