Statistical Area Level 2

Statistical Areas Level 2 (SA2) are medium-sized general-purpose areas built up from whole Statistical Areas Level 1 (SA1). Their purpose is to represent a community that interacts together socially and economically.

There are 2,571 SA2s covering the whole of Australia without gaps or overlaps. This includes 19 non-spatial special purpose codes representing populations that are difficult to define geographically such as people in transit or have no fixed address. Migratory - Offshore - Shipping and No Usual Address are examples of this type of SA2.

SA2s are generally the smallest areas used for the release of ABS non-Census of Population and Housing statistics, including Estimated Resident Population and Health data. Whole SA2s aggregate to form Statistical Areas Level 3 (SA3).

SA2s are also used to build Significant Urban Areas.

SA2s are designed using multiple criteria, listed below in approximate order of importance.

SA2s generally have a population between 3,000 and 25,000 with an average of about 10,000 people. SA2s in remote and regional areas generally have smaller populations than those in urban areas. There are some SA2s outside these target population ranges due to other considerations including:

• The relative sparseness of the population in remote regions (an SA2 with a population of 3,000 may cover too large and diverse geographic area to be meaningful).
• The benefit of preserving recognisable areas for which there is a considerable amount of historical data.
• Isolated geographic areas, such as islands or other isolated populations.
• The need to avoid subdivisions of otherwise coherent regions, such as very large suburbs or regional towns.

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. The concept of a functional area is used at all levels of the ABS Main Structure and is particularly essential to the design of SA2s outside of major urban areas.

A centre and its functional area are represented by one or more SA2s. A rural town and its functional area may be combined into a single SA2. A larger town may be identified by a single SA2 and its functional area around the town by a second SA2. Larger towns and regional cities may be represented by several SA2s.

Within cities, SA2s represent officially recognised suburbs rather than functional areas.

In remote areas, SA2s are designed to represent meaningful regions, useful for statistical analysis.

SA2s containing regional towns or located on the fringes of larger cities are designed to contain the urban area, any immediately associated semi-urban development, and likely growth areas in the next 10 to 20 years. This is to ensure that SA2s remain stable over several population and housing censuses.

Where possible, SA2s consist of whole officially recognised suburbs or rural localities. This is to make the regions as meaningful as possible to those unfamiliar with statistical geography.

In regional and remote areas, officially recognised localities are usually too small to be represented by a single SA2 and are combined with neighbouring areas to represent a functional area or a meaningful region.

In major cities, SA2s often represent single suburbs. Suburb size is variable within and between cities and they do not always make a convenient region to be used directly as an SA2. Where this occurs, five general criteria are used to cluster smaller suburbs together or break up extremely large suburbs:

• shared road networks
• shared community facilities
• Local Government Areas
• shared historical or social links
• socio-economic similarity.

Local Government Areas (LGA) are considered in the design of SA2s and are often adopted where the LGA boundary satisfies one or more of the following:

• closely aligns with officially recognised suburb boundaries
• reflects the underlying settlement pattern
• represents the functional area of a regional town or city
• has a high degree of recognition among stakeholders
• aligns to a significant recognisable geographic feature.

Zero SA2s are designed to have no population. They are created to represent large unpopulated areas that are not easily combined with surrounding populated SA2s.

They may include:

• major infrastructure (such as ports and airports)
• significant bodies of water
• major commercial and industrial zones
• national parks
• defence land
• very large urban parks
• very large sporting precincts.

The key criteria for SA2 names are that they:

• are meaningful
• have a maximum of 50 characters
• are unique, that is not shared by any other SA2 in Australia.

In large urban areas, SA2s are named for the officially recognised suburbs they contain.

• Where an SA2 is made from a single suburb, it will retain the name of the suburb, for example “Curtin”.
• Where a single large suburb is split into more than one SA2, it will retain the name of the suburb and a geographic identifier, for example “Mount Waverley – North”.
• Where an SA2 is made up from 2 or 3 suburbs, the SA2 name is a concatenation of the suburb names, for example “Greenfield Park – Prairiewood”.
• Where an SA2 is made up of 4 or more suburbs it will be named for the larger or more prominent suburbs, or given a local identifier, for example “Belgrave - Selby”.

In rural areas, SA2s are named for the officially recognised localities they contain, or the towns, cities, or regions with which they are associated, for example:

• Benalla Surrounds
• Townsville – South
• Bulahdelah – Stroud.

Since ASGS Edition 3, SA2s that contain the town and surrounding area use the name “X Region”. For SA2s that do not contain the town but include the surrounding area, the name “X Surrounds” is used. For example, “Cooma Surrounds”, does not include the town of Cooma but the surrounding area around the town.

Where an SA2 name appears in 2 or more state and territories, the state or territory abbreviation is attached to the SA2 name, for example:

• O’Connor (ACT)
• O’Connor (WA).

An SA2 is identifiable by a 9-digit hierarchical code comprising a 1-digit State and Territory identifier, and Statistical Areas Level 2-4 identifiers. The SA2 identifier is a 4-digit code, assigned in alphabetical order within an SA3.

An SA2 code is unique when it is preceded by the State or Territory identifier.

If an SA2 is discontinued, or changes significantly, the SA2 identifier is retired and the next available unused identifier will be applied. Changes at higher level geographies within the structure may also result in a code change for the SA2. For example, if a new SA3 is created, existing SA2s will be allocated a new code to reflect the change in SA3 identifier. More information about identifying change, including code changes, is in Changes from the previous edition of the ASGS.