Do you have HVAC? Maybe some of my difficultly understanding is being American I'm in a hotter, much more humid climate, so we've got central HVAC. A key feature of heat pumps isn't just that it lowers the temperature of the air, it also reduces humidity.
I've got a lot of exposure to new home construction here and can tell you I don't even know what "damp proofing" is, and our bathrooms don't need special paint. They're ventilated and we have HVAC. Beyond that, if homeowners take 30 minute showers with scalding hot water and the door closed then, well, the outcome is inevitable no matter what you do. Not just mold but you'll start damaging fixtures, etc.
It's hard to get old caulking clean and keep it mold free, just gotta recaulk regularly, but I'm somewhat skeptical of blaming paint.
I've got a lot of exposure to new home construction here and can tell you I don't even know what "damp proofing" is, and our bathrooms don't need special paint. They're ventilated and we have HVAC. Beyond that, if homeowners take 30 minute showers with scalding hot water and the door closed then, well, the outcome is inevitable no matter what you do. Not just mold but you'll start damaging fixtures, etc.
It's hard to get old caulking clean and keep it mold free, just gotta recaulk regularly, but I'm somewhat skeptical of blaming paint.