The average Canadian spends approximately 90% of their time indoors. So having and maintaining comfortable and healthy indoor environments is critical for good building design. Since the 1980s, concern for occupant health has increased and translated into more demanding performance requirements for materials selection and installation, ventilation practices and commissioning and monitoring protocols.

Many building products contain chemicals that evaporate or “off-gas” for several days or weeks after installation. If large quantities of these products are used inside a building, or products with particularly strong emissions are used, they pollute the indoor air. Other products readily trap dust and odors and release them over time. Building materials can also support growth of moulds and bacteria, particularly if they become damp, potentially causing allergic reactions, respiratory problems and persistent odours - symptoms of "sick-building syndrome".

In recent years, several lawsuits with large damage awards have been won by building occupants suffering from health problems linked to chemicals off-gassed from building materials, setting legal precedents across North America. This has prompted many insurance companies to examine their policies and their clients’ design and construction methods. Following a rigorous selection procedure for construction materials, aimed at minimizing occupant chemical exposure, is an effective way to reduce health risks – and exposure to liability by building developers, designers, contractors and operators.

Considerations for Indoor Environmental Quality include:

Thermal Comfort
Employee health and productivity are greatly influenced by the quality of the indoor environment.   Poor air quality and lighting levels, off-gassing of chemicals from building materials, and the growth of moulds and bacteria can adversely affect building occupants.  Sustainable design supports the well-being of building occupants by reducing indoor air pollution through the selection of materials with low off-gassing potential and ventilation strategies, providing access to daylight and views, and controlling lighting, humidity, and temperature levels for optimum comfort.

Daylighting
The intention is to provide a connection between indoor spaces and the outdoors for the building occupants through the introduction of daylight and views into the regularly occupied areas of the building.