Ventilation of residential buildings: Impacts on the occupants' respiratory health

A residential building’s indoor air can theoretically contain various types of contaminants to which the occupants could be exposed. Many studies have established links between the presence of indoor air contaminants and some health problems. A reduction in indoor air contamination must ideally be the subject of a strategy encompassing a certain number of measures, with control at source definitely being the first option to be considered. However, this approach alone is not sufficient to reduce all of the contaminants present, so other complementary measures need to be considered, such as the ventilation of indoor spaces.

At the present time, the application of regulations on the ventilation of small residential buildings varies greatly in Québec, with municipalities having the power to adopt their own construction regulation. The Régie du bâtiment du Québec (RBQ) wants to adopt a uniform basic standard for all new buildings, particularly concerning the installation of mechanical ventilation systems. However, the RBQ is running into some resistance, considering the technical, legal and socioeconomic difficulties that may arise from the application of such a measure. In addition, professionals from municipalities and the housing community, as well as consumers, are generally poorly informed about the actual ventilation issues pertaining to indoor air quality and the occupants’ health.

To do so, we have reviewed the main technical and regulatory aspects relating to the ventilation of residential buildings and analyzed the scientific literature on the direct and indirect relationships between ventilation and the occupants’ respiratory health. We then summarize our reflection on the quality of the scientific evidence, the applicability of the results to Québec, the application and determination of a minimum ventilation rate and, finally, on the factors likely to affect ventilation efficiency.