Methodology

The Australian Statistical Geography Standard (ASGS) is a hierarchical spatial classification designed to meet user needs and classification principles.

The ASGS meets broad user needs for geospatially enabled social, demographic, and economic statistics. It facilitates the publication and analysis of official statistics and other data below the state or territory level. To do this, the ASGS is designed to be:

• useful and relevant for data dissemination
• flexible for aggregation into larger geographic units
• useful building blocks for user-defined regions.

The ASGS is designed on the following classification principles:

• Members within one class are of the same type.
• Classes are uniquely defined to be mutually exclusive.
• In total, the members in each class cover the entire class.

As a result, the geographies within each hierarchical structure of the ASGS are:

• of the same type and delimited by well-defined criteria
• clearly defined by precise boundaries
• uniquely identified by codes and names
• mutually exclusive
• aggregated to cover the whole of Australia.

ASGS Edition 4 was designed in a GIS environment, beginning with Mesh Blocks. Groups of one or more Mesh Blocks aggregate to form a Statistical Areas Level 1 (SA1). One or more SA1s aggregate to form a Statistical Areas Level 2 (SA2), and so forth.

Before implementing changes, the ABS conducted a review which included consultation with key stakeholders, and via the ABS Consultation Hub. Outcomes from the review are available in the Outcomes from the review of the Australian Statistical Geography Standard (ASGS) publication.

Changes to ASGS boundaries balance stability and continuity with earlier editions against the need to maintain relevant boundaries and support time series analysis. To support this, ASGS Edition 3 geographies were used as the base dataset, and changes focused on:

• areas identified by ASGS users, including government and the public, where the ASGS was reported as not meeting user needs
• priority growth areas, identified using quarterly updates to the ABS Address Register. These were generally inner-city areas and locations on the edges of capital cities.

Changes were determined using ABS population data, local planning information, and aerial imagery, in combination with the ASGS design criteria outlined in this publication. Boundaries were preferentially aligned to road datasets, land parcels and property boundaries where possible.

Main Structure boundaries were updated to account for growth and change in Australia’s population, economy and infrastructure since ASGS Edition 3, to reflect conditions on Census night 2026 as accurately as possible.

The ABS uses multiple definitions of Australia. The ASGS uses the geographic definition of Australia, as set out in section 2B of the Acts Interpretation Act 1901, which defines Australia or the Commonwealth as:

‘…the Commonwealth of Australia and, when used in a geographic sense, includes Norfolk Island, the Territory of Christmas Island and the Territory of Cocos (Keeling) Islands, but does not include any other external Territory’.

Geographic Australia includes:

• States of New South Wales, Victoria, Queensland, South Australia, Western Australia, and Tasmania
• Northern Territory
• Australian Capital Territory
• Territory of Cocos (Keeling) Islands
• Territory of Christmas Island
• Jervis Bay Territory
• Norfolk Island

Historically, Norfolk Island was excluded from the definition of Geographic Australia. In 2015, the Australian Government announced reforms to the governance of Norfolk Island. From 1 July 2016, the definition of Geographic Australia included Norfolk Island.

Norfolk Island, Jervis Bay Territory, the Territory of Cocos (Keeling) Islands, and the Territory of Christmas Island together form the Other Territories category within the ASGS at the state and territory level.

ASGS boundaries do not feature Macquarie Island, although it is legally part of Tasmania. Macquarie Island is an extremely isolated sub-Antarctic island in the Southern Ocean which has no permanent population. Any population on Macquarie Island, for example on scientific expeditions, is recorded in the Census of Population and Housing and is included in the ‘Migratory - Offshore - Shipping’ Statistical Areas Level 2 for Tasmania.

To avoid creating geographic gaps in ASGS boundaries, the ASGS includes territorial enclaves owned or rented by other countries in Australia. For example, embassies, consulates, scientific stations, information and immigration offices.

Please refer to relevant ABS publications regarding any inclusions or exclusions for statistical release.

Area is a general term that can be used when referring to part of the Earth’s surface. It is used interchangeably with region throughout the ASGS publication.

Boundaries are lines drawn to separate and represent different regions or areas on the Earth’s surface.

Discrete areas are individually distinct and identifiable from other populated locations. For example, Thredbo Village in New South Wales.

A functional area is the area from which people come to access services at a centre. This centre may be a rural town, a regional city, a commercial and transport hub within a major city, or the major city itself.

A geographic area is used to describe the defined areas that make up each of the ASGS structures. For example, Mesh Blocks are the smallest geographic areas defined by the ABS.

Geographies, in the context of the ASGS, refers to the individual structures that make up the classification.

Within the Urban Structure of the ASGS, a Locality generally has a population of 200 to 999 ‘usual residents’. However, a Locality may contain a population exceeding 999 usual residents if it does not meet the ASGS design criteria for an Urban Centre.

Also see Suburbs and Localities.

Location describes a geographical area or place on the Earth’s surface. Location data refers to information that includes a location component and is often used when referring to geospatial information.

An Australian postcode is a four-digit code created and maintained by Australia Post for mail delivery. Postcodes are not designed for the collection or analysis of statistics. However, many people use it as a proxy to represent geographic regions for their data.

The ABS approximates postcode boundaries using Mesh Blocks, called Postal Areas (POA). Authoritative postcode boundaries are not publicly available. Postcodes are not recommended as a source of geocoding information, and care should be taken when using postcodes or ABS Mesh Block approximation POAs for statistical analysis.

Also see Postal Areas.

Postal Areas (POA) are Mesh Block approximations of a generalised definition of Australian postcodes.

The ABS Postal Areas (POA) are part of the ASGS Non ABS Structures. Since ASGS Edition 2 (2016), POAs have been approximated from Mesh Blocks using the best available information on postcodes. Authoritative postcode boundaries are not publicly available. Postcodes are not recommended as a source of geocoding information, and care should be taken when using postcodes or ABS Mesh Block approximation POAs for statistical analysis.

Also see Postcodes.

Region is a general term for a geographic area or boundary of any type. For example, Suburb, Local Government Area, SA1 to SA4, Remoteness Areas. A region may include all or part of an urbanised area, including capital cities.

Regional refers to areas outside major cities. Inner Regional Australia and Outer Regional Australia are categories within the ASGS Remoteness Structure.

There is no single definition of remoteness or Remote Australia, nor agreed terminology to describe this concept. Remote Australia, in the context of the ASGS, is a category within the ASGS Remoteness Structure used for the purpose of releasing and analysing statistics.

For the purposes of the ASGS, rural refers to areas not urban, and categorised for statistical purposes into the Bounded Locality and Rural Balance categories of the Section of State (SOS) structure, within the ASGS Urban Structure.

Also see Urban.

Social geography is a general term which refers to the location of people and communities.

Statistical Areas are geographic units defined in the ASGS Main Structure. For example, SA1, SA2, SA3, and SA4.

A statistical geography is a structure made up of geographic units which together cover the entire area for which statistics are collected, analysed, and published. In the ASGS, this area is Geographic Australia.

Suburbs refer to the officially recognised boundaries of suburbs (in cities and larger towns) and localities (outside cities and larger towns), as defined by Australian state and territory governments. The ABS uses these boundaries to create Suburbs and Localities within the ASGS Non ABS Structures.

Also see Suburbs and Localities.

Suburbs and Localities (SAL) are a structure within the ASGS Non ABS Structures. SALs enable the release of ABS data on areas that approximate officially recognised boundaries of suburbs and localities. SALs are approximated using one or more Mesh Blocks. SALs were referred to as State Suburbs (SSC) in past editions of the ASGS.

The ABS does not explicitly define towns. However, the ABS approximates urban centres and localities with populations of 200 or more people in the Urban Centres and Localities (UCL) geography.

There are many small towns with populations of less than 200 people that are not included within UCLs. These small towns and other urban areas are represented by officially recognised localities. The ABS provides Census data through Mesh Block approximated Suburbs and Localities (SAL) within the ASGS Non ABS Structures.

For the purposes of the ASGS, urban refers to areas not rural, and categorised for statistical purposes into the Major Urban, and Other Urban categories of the Section of State (SOS) structure, within the ASGS Urban Structure.

Also see Rural.

Urban Centres and Localities (UCL) is a statistical geography within the ASGS Urban Structure, representing areas of concentrated urban development. In accordance with UCL design criteria:

• An Urban Centre generally has a core urban population of 1,000 or more people.
• A Locality generally has a population between 200 and 999 people.

For statistical purposes, people living in Urban Centres are classified as urban, while those in Localities are classified as rural.