Mold also forms when a room is ventilated. Mold is possible where there is constant moisture. This occurs when warm and therefore quite humid air condenses in a joint, corner, angle, or niche because it is colder there due to defects in the thermal insulation, it also dries poorly there, and suddenly the enemy is there. I am also a fan of monolithic walls because no insulation errors can occur there since there is no insulation; the insulation is the thick Ytong stone itself, and it is uniformly built in everywhere. There is no plastic film in the wall; a cement and aerated concrete wall absorbs moisture and releases it if you do not block it from the inside with sealing wall coverings. Ventilation is still necessary, but our window rebate things are sufficient; when we return from vacation, there is no need to fear finding mold because all the windows were closed for two weeks.