Notes on the data: Housing, rent assistance and vehicle access

Crowded dwellings - persons living in crowded dwellings; and persons living in 'severely' crowded dwellings 2021


Policy context: For Australian agencies such as State/Territory housing authorities and the Australian Bureau of Statistics (ABS), household crowding is defined according to the Canadian National Occupancy Standard (CNOS), a widely-used guideline for assessing whether a household has a sufficient number of bedrooms for household members The CNOS is based on measuring the number of people per bedroom in each dwelling in the context of the ‘norms’ of sleeping and living associated with the culture of a western nuclear family. Rather than a simple ‘crowding’ definition based on how many people are living in each bedroom, it is based on a nuanced understanding of the social and family relationships of those in the dwelling, including the number of usual residents, their relationships, age and sex [1].

At the 2021 Census, 6.6% of the population were assessed as living in a crowded dwelling (17.2% of the Aboriginal population, compared with 6.2% of the non-Indigenous population) [4].

A 'severely' crowded dwelling requires four or more extra bedrooms to adequately accommodate its usual residents according to the principles of the CNOS. The ABS categorises people living in ‘severely’ crowded dwellings in one of six ABS homeless groups [2]. People living in severe overcrowding are considered to lack control of and access to space for social relations (one of the key elements of the ABS definition of homelessness) and are considered not to have accommodation alternatives when remaining in such extreme living arrangements [3]. At the 2021 Census, 20.4 persons per 10,000 population were assessed as living in a severely crowded dwelling (197.6 Aboriginal people per 10,000 Aboriginal population compared with 14.4 per 10,000 non-Indigenous people for the non-Indigenous population [4].

The health and safety of occupants may not be compromised in instances of slight overcrowding or short-term overcrowding; severe and sustained overcrowding can however put their health and safety at risk [3].

People living in 'severely' crowded dwellings have been the largest homeless group in each of the last four Censuses. Although the number of people in this group fell slightly between 2001 and 2006, increases of 31% and 23% of people living in ‘severely’ crowded dwellings in 2011 and 2016, respectively accounted for the majority of the rise in homelessness in these periods. Moreover, New South Wales contributed to most of the increase in 2016 with an 74% increase to 16,821 persons from 9,655 persons in 2011 [3].


  1. Australian Housing and Urban Research Initiative (AHURI). When is a dwelling considered 'crowded' and 'severely crowded', AHURI Brief, 2019 (May). URL:, accessed 8 August 2019.
  2. Australian Bureau of Statistics (ABS). Information Paper - Methodology for Estimating Homelessness from the Census of Population and Housing 2012. Cat no. 2049.0.55.001 URL:, accessed 8 August 2019.
  3. Australian Bureau of Statistics (ABS). Census of Population and Housing: Estimating Homelessness, 2016. Cat no. 2049.0. URL:!OpenDocument, accessed 8 August 2019.
  4. Data from PHIDU workbooks, data release November 2022, available from:

Notes: The Canadian National Occupancy Standard assesses the bedroom requirements of a household, accounting for both household size and composition, specifying that:

  • there should be no more than two persons per bedroom
  • children less than five years of age of different sexes may reasonably share a bedroom
  • children less than 18 years of age and of the same sex may reasonably share a bedroom
  • single household members 18 years and over should have a separate bedroom, as should parents or couples and
  • a lone person household may reasonably occupy a bed-sitter.

'Severely' crowded dwellings are those assessed as needing four or more additional bedrooms to accommodate all persons currently living in the household, according to the Canadian National Occupancy Standard (see Persons living in crowded dwellings above).


Private dwelling: A private dwelling can be a house, flat or even a room. It can also be a caravan, houseboat, tent, or a house attached to an office, or rooms above a shop.


Geography: Data available by Population Health Area, Local Government Area, Primary Health Network, Quintile of socioeconomic disadvantage of area and Quintiles within PHNs, and Remoteness Area


Numerator: Persons living in private dwellings requiring extra bedrooms


Denominator: Persons living in all occupied private dwellings


Detail of analysis:

Persons living in crowded dwellings: Per cent

Persons living in severely crowded dwellings: Rate per 10,000


Source: Compiled by PHIDU based on the ABS Census of Population and Housing, August 2021


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