Passive buildings are super airtight – what about moisture and mould problems?

Passive buildings do require an extremely airtight building envelope, perhaps 25 times tighter than a conventional building in Australia. Does this lead to moisture and mould? Well, without adequate ventilation, insulation and an airtight barrier it would but of course, this is exactly how Passive House Buildings must be designed. With constant, low-level ventilation a major preventative of moisture problems in addition to maintaining excellent air quality, Passive House professionals are highly aware of designing out moisture and mould and can often undertake detailed modelling (if required) to identify and address potential moisture issues with a variety of techniques during the design.