Interior insulation
Interior insulation is never without risk
Insulating on the inside of houses is construction physically (almost) impossible to execute correctly without damage. It is however easily recommended by manufacturers. Often there is a risk of internal condensation and accompanying mold. In practice we haven’t seen any execution without any visible or measurable damage, let alone hidden mold.
Only with renovations you can see by the colour (and often the smell) of the insulation material that it isn’t a healthy situation. If a renovated room stays completely closed for 3 days and you notice a smell upon entering, then there are probably mold spores flying around. Because water is by definition odourless.
A lot of mold types produce very toxic mycotoxins and are harmful for your health. Independent studies also confirm that many health problems can be directly related to hidden mold colonies. A specific investigation can bring clarity.
An additional problem is the cooling of the outer walls with cracks and tears by the cooperation of the internal condensation, the shifting of the dew point and cold frost periods.
So think and prevent these problems.