The ABS defines a group household as a household consisting of two or more unrelated people where all persons are aged 15 years and over. There are no reported couple relationships, parent-child relationships or other blood relationships in these households.
An unrelated child (e.g. boarder) under the age of 15 who lives in a household with one or more usual residents, is coded as forming a parent-child relationship within that household. These households become family households, not group households.
Group households are classified in the variable Household Composition (HHCD), and individual members are classified in Relationship in Household (RLHP).
See also Child, Family, Household, Household Composition (HHCD), Relationship in Household (RLHP).