Household and family composition

Households and families

The ABS defines a household as one or more people, at least one of them aged 15 or over, who usually live in the same private dwelling, so for Census purposes the number of households equals the number of occupied private dwellings. A family is two or more people, at least one aged 15 or over, who are related by blood, marriage (registered or de facto), adoption, step or fostering and who usually live in the same household. A household holds no family, one family or several, and people living with a family who aren't related to it are not counted as family members unless they are under 15.

Household composition (the ABS variable HHCD) has three main types. A family household contains at least one family, and the ABS separates one family households from multiple family households and records whether unrelated people live there too. A lone person household has only one person aged 15 or over. A group household is two or more unrelated people, all aged 15 or over. Visitor-only households and other non-classifiable households, mainly dwellings with no form returned, fall outside these three types, and other non-classifiable households were 3.8% of occupied private dwellings in 2021.

Family types and children

Family composition (FMCF) builds each family around a family reference person, usually Person 1 on the form, and classifies it as one of four types:

• Couple family without children: a couple living together, with or without other relatives.
• Couple family with children: a couple and at least one child of any age.
• One parent family: a lone parent with at least one child of any age and no partner in the household.
• Other family: related people who don't form a couple or parent-child relationship, such as adult siblings living together.

The ABS splits children into three types. A child under 15 is any child under 15 who forms a parent-child relationship in the household. A dependent student is aged 15 to 24 and studying full-time at a secondary or tertiary institution. A non-dependent child is aged 15 to 24 and not a full-time student, or aged 25 or over. Couple and one parent families are then split by whether they include children under 15, dependent students and non-dependent children. A household can have up to three families classified separately.

At the 2021 Census, Australia had 6,730,187 families: 43.7% were couples with children, 38.8% couples without children, 15.9% one parent families and 1.6% other families. Of classifiable households, 70.5% were family households, 25.6% lone person households and 3.9% group households, with an average of 2.5 people per household.

Reading the two counts

Household and family counts for the same area measure different things, so they don't match. Lone person and group households contain no family, which lowers the family count, and a multiple family household contains two or more, which raises it. In 2021 Australia had 6,542,648 family households and 6,730,187 families, a difference of about 187,500, consistent with second and third families living in multiple family households.

For a site, households are the unit for dwellings, rent, mortgage repayments and household income, so they suit questions about housing demand and spending at the front door. Families suit questions about parents and children. A couple family with children can include adult sons and daughters living at home, so a suburb's share of couples with children overstates its young families, and the split by children under 15 and dependent students is the better figure for childcare, schools or family retail.

Household and family composition and Censible

Censible has both classifications for any area or catchment: the shares of households that are family, lone person and group households, average household size and household size from one to six or more people, and the shares of families that are couples with children, couples without children, one parent families and other families. Couple and one parent families are also split by the age of their children. Household shares are of occupied private dwellings and family shares are of families, so the two sets don't add up to each other.

Sources: ABS, Census Dictionary 2021, Household composition (HHCD); ABS, Census Dictionary 2021, Family composition (FMCF); ABS, 2021 Census QuickStats, Australia.