Regions

SA1

The Statistical Area Level 1 (SA1) is the second smallest geographic area defined in the Australian Statistical Geography Standard (ASGS), the smallest being the Mesh Block. The SA1 has been designed for use in the Census of Population and Housing as the smallest unit for the processing and release of Census data. For the 2011 Census, SA1s will also be the basis of output for most data, the exception being some Place of Work destination zones. For 2011, SA1s also serve as the basic building block in the ASGS and are used for the aggregation of statistics to larger Census geographic areas.

An SA1 is represented by a unique seven digit code.

SA1s are designed to remain relatively constant over several Censuses. Future change will largely be dealt with by splitting existing SA1s. For the 2011 Census, there are approximately 54,000 SA1s throughout Australia (this includes the other territories of Christmas and Cocos (Keeling) Islands and Jervis Bay). SA1s cover the whole of Australia with no gaps or overlaps.

Special SA1s:

  • Zero population SA1s are created in areas that are expected to have little or no permanently residing populations. Data from these areas are reassigned to a populated alternate SA1.
  • Shipping SA1s contain people who are enumerated aboard ship in Australian waters. This includes commercial cargo vessels, passenger liners, ocean going passenger/car ferries, and dredges. People enumerated on board commercial vessels between Australian ports are also attributed to Shipping SA1s. Foreign crews on ships are excluded from Census enumeration. There is one Shipping SA1 for each state, the Northern Territory and Other Territories.
  • Off-Shore SA1s contain people who are enumerated on off-shore oil rigs, drilling platforms and the like. There is one Off-Shore SA1 for each state and the Northern Territory. Census data from respondents who completed their Census forms in the Australian Antarctic Territory are coded to an additional Off-Shore SA1 in Tasmania.
  • Migratory SA1s contain people who are enumerated on an overnight journey by train or bus. There is one Migratory SA1 for each state, the Northern Territory and the Australian Capital Territory.

POA

Postal Areas are ABS approximations of Australia Post postcodes, created by allocating whole Statistical Areas Level 1 (SA1s) on a 'best fit' basis to postcodes.

Census Postal Areas exclude non-mappable Australia Post postcodes such as:
post office box postcodes; some delivery route postcodes, which are also covered by other postcodes (a situation which often occurs in rural areas); and
some postcodes which, because of the application of the 'best fit' principle, do not get an SA1 allocated to them.

This means that there are more Australia Post postcodes than Census Postal Areas.

Every SA1 is allocated one valid Australia Post postcode as the Postal Area for that SA1. When a person is enumerated in that SA1, the Postal Area is allocated to the person as their Postal Area of enumeration.

When a person's address is coded to their SA1 of Usual Residence, the Postal Area of the SA1 is allocated to the person as their Postal Area of Usual Residence.

SED

A State Electoral Division is an area legally prescribed for the purpose of returning one or more members to the state or territory lower houses of parliament. Queensland has only one house of parliament at the state level, with each member representing an electoral district. State Electoral Divisions are approximated by aggregating the data for Statistical Areas Level 1 (SA1s) that best fit the area.

CED

A Commonwealth Electoral Division (CED) is an area legally prescribed for the purpose of returning one or more members to the federal lower house of parliament. CEDs are approximated by aggregating the data for Statistical Areas Level 1 (SA1s) that best fit the area.

Commonwealth Electoral Divisions have different boundaries to State Electoral Divisions (SEDs), except in Tasmania and the ACT where they are the same. CEDs cover all of Australia.