Indoor air quality is a significant health and well-being concern in domestic and commercial settings. Demonstrating that a building offers good indoor air quality increases a development scheme's environmental and sustainability value. It is an issue considered in the BREEAM and WELL assessment processes.

A BREEAM indoor air quality assessment is a process that evaluates how a building's design and construction can achieve a healthy and comfortable indoor environment for its occupants. It considers the following aspects:

1. The sources and levels of pollutants in the indoor air, such as volatile organic compounds (VOCs), formaldehyde, nitrogen oxides (NOx), particulate matter (PM10), carbon monoxide (CO) and carbon dioxide (CO2).

2. The ventilation strategy and system, including the type, location, operation and maintenance of ventilation units, filters, ducts and air inlets and outlets.

3. The selection and installation of building materials, finishes, furnishings and equipment and their potential emissions of pollutants or odours.

4. The commissioning and testing of the ventilation system and the indoor air quality, including the methods, standards and frequency of sampling and analysis.

5. The provision of information and guidance to the building users and managers on how to maintain and improve the indoor air quality.

To achieve BREEAM credits for indoor air quality, the project team must develop and implement an indoor air quality plan (IAQP) that covers the above aspects and follows the guidance provided by BREEAM. The IAQP must be reviewed and updated throughout the design and construction stages and verified by post-construction testing.

The project team must also demonstrate compliance with the relevant national and international standards and regulations for indoor air quality.