> A hermetically sealed home with no insulation is generally warmer than a leaky home with walls stuffed with insulation.
Warmer, maybe, but bad for people and good for fungi. Many contemporary buildings are built too airtight, lacking natural ventilation, which causes huge problems with interior air quality and traps moisture inside structures, creating places for mold to thrive.
Airtight buildings are perfectly fine with a proper Heat recovery ventilation system (HRV) that they should be using. HRV's are mandatory when building the PassiveHaus spec.
True. Unfortunately, at least around here a lot of buildings have been built in the past five or so decades that are fine insulation-wise but sorely lacking in ventilation, natural or otherwise, leading to widespread health issues. Many prefab concrete buildings from the 60s and 70s, even 80s, are practically ready for demolition.
Warmer, maybe, but bad for people and good for fungi. Many contemporary buildings are built too airtight, lacking natural ventilation, which causes huge problems with interior air quality and traps moisture inside structures, creating places for mold to thrive.