This study assess the measurement of overcrowding in Australia and explores the relationships between various household density measures and the wellbeing of occupants. Indicators of the incidence or severity of household crowding in Australia actually measure occupant density—the ratio of occupants to available space—rather than crowding, which relates to a psychological response to the sense of excessive density. How overcrowding is defined and measured has important implications for funding requirements, the appropriate mix of housing stock given household structures and rules for allocating families to public and community housing.

There is a complex relationship between occupant density and wellbeing within and across households. Any measure based only on readily observable metrics of household composition and the number of bedrooms is unlikely to accurately discriminate between households that are overcrowded—in that occupants are suffering significant adverse effects from excessive density—from households that are not overcrowded. While such measures may have some descriptive value, they will not adequately meet informational needs for many policy and practice purposes, including the targeting of assistance.

The experiences of people from culturally and linguistically diverse (CALD) and Indigenous backgrounds living in overcrowded households were explored in qualitative interviews. The interviews revealed substantial negative effects, including lack of privacy, excessive noise, antisocial behaviour, child safety and wellbeing concerns, increased housework, food theft, and family and financial strain. Service providers are also impacted by having to manage additional repairs and maintenance, provision of intensive tenancy support and the need to reallocate tenants.

Some positive effects were noted, including caring for family members, strengthened family ties, promotion of cultural identity, companionship and financial benefits. The realisation of benefits generally relies on the household being well-functioning.