Some information on the structure of Private dwellings has been collected for all censuses since 1911, though the specific types of classification used have varied significantly.
Cabins and Houseboats
Prior to the 1986 Census, occupied craft in marinas were treated as Non-private dwellings, however occupied houseboats and occupied small boats are now treated as Occupied private dwellings.
Collection methods before 2016
From 1976 to 2011, the information on Dwelling structure was collected by Census Field Officers in the Collector Record Book at the time the Census forms were delivered instead of being on the Census form.
In 2016 there was a change in the way the data was collected. It was initially recorded by ABS Address Canvassing Officers in the lead up to the Census, as part of establishing the Address Register as a mail-out frame for designated areas (93% of Australian addresses). In areas enumerated using the traditional approach of delivering forms, the information was collected by ABS Field Officers during the Census collection period. Location of private dwelling data was also updated as required by ABS Field Officers during the Census enumeration period. Dwellings in remote areas continue to have their structure collected solely by field officers.
In 2021, the Address Register is considered the main source of Dwelling location data, and real-world frame amendments are made when appropriate, by Field and Office staff.
For the 2016 Census, there was a change to one of the response categories for this variable. The previous category of 'Caravan, cabin or houseboat' was separated into two categories:
In 2021, there has been further disaggregation of the flat/apartment categories to align with different building rules in place for buildings with a height greater than 25 metres and to meet increasing stakeholder demand for more data about high rise apartment buildings. The previous category ‘In a four or more storey block’ is separated into two categories:
- In a four to eight storey block
- In a nine or more storey block
Separate house and semi-detached definitions
For the 2021 Census, there is a change to the half a metre rule that had previously distinguished separate houses from semi-detached dwellings. The new definition is purely structural in which a separate house (constructed in the last 20 years) must be structurally independent, regardless of separation from adjacent dwellings. This change aligns with the way structure data is provided for the Building Approvals collection. See Housing variables for more information.
Missing dwelling structure
For the 2021 Census, addresses that do not have Dwelling structure recorded from observation or by the ABS address register can have the information populated by imputation.