Mould growth affects one in three homes, and it is the biggest cause for complaints and litigations filed to the relevant authorities in Australia, while also significantly affecting the physical and psychological health of the building’s occupants. Indoor mould is caused by excessive dampness, resulting from poor architectural specification, construction and maintenance practices, as well as inappropriate behaviour of the occupants. The consequences range from early biodeterioration of building materials, requiring anticipated renovation works, to deterioration of the indoor environment, posing a serious threat to the building’s occupants. This study investigates indoor air quality (IAQ) and mould growth, providing a snapshot of the current IAQ of Australian residential buildings regarding air pollutants. It uses a case study representative of the typical Australian suburban home to investigate the effects of unnoticed mould growth. The results of the monitoring campaign indicate that buildings with a high concentration of fungal spores are also more likely to present poor IAQ levels, high concentrations of particulate matters (PM10and PM2.5) and carbon dioxide (CO2). This research suggests the need for the development of early detection strategies that could minimise the health hazard to people, thereby preventing the need for any major renovations.