Many residents are unaware of the fact that they should regularly ventilate their dwellings and how they should go about doing this. Inadequate or insufficient ventilation causes moisture damage to a dwelling and is likely to reduce its quality. Also, it is hugely energy-consuming to heat poorly ventilated dwellings, with their steamed-up windows, moisture stains on the walls and wood rot in floors, frames, beams and joints.
More importantly though, mould and house dust mites caused by incorrect or poor ventilation, can result in health problems. The risk of asthma among children living in humid dwellings increases by a factor of 1.5 - 3.5; among adults a bit less. The occurrence of coughing, respiratory difficulties, chronic colds, headaches and all kinds of allergies is also reported to be more frequent in humid dwellings.

Female residents from the district of Overtoomse veld are now being trained to become Certified Ventilation Advisors. Through door-to-door advises and ventilation audits they show residents how to ventilate their dwellings in a sensible way. They inform them about the necessities of correct ventilation on one hand and the consequences of poor ventilation on the other hand.