This dataset is the definitive set of statistical area 1 (SA1) boundaries for 2018 as defined by Stats NZ.This version contains 29,889 SA1s.SA1 is a new output geography that allows the release of more detailed information about population characteristics than is available at the meshblock level. Built by joining meshblocks, SA1s have an ideal size range of 100–200 residents, and a maximum population of about 500. This is to minimise suppression of population data in multivariate statistics tables.The SA1 should: form a contiguous cluster of one or more meshblocks be either urban, rural, or water in character be small enough to: allow flexibility for aggregation to other statistical geographies allow users to aggregate areas into their own defined communities of interest form a nested hierarchy with statistical output geographies and administrative boundaries. It must: be built from meshblocks either define or aggregate to define SA2s, urban rural areas, territorial authorities, and regional councils.SA1s generally have a population of 100–200 residents, with some exceptions:SA1s with nil or nominal resident populations are created to represent remote mainland areas, unpopulated islands, inland water, inlets, or oceanic areas.Some SA1s in remote rural areas and urban industrial or business areas have fewer than 100 residents.Some SA1s that contain apartment blocks, retirement villages, and large non-residential facilities have more than 500 residents.The SA1 classification is a flat classification and in 2018 contains 29,889 SA1s – 29,873 digitised and 16 non-digitised. SA1s are not named. SA1 codes have seven digits starting with a ‘7’ and numbered approximately north to south. As new SA1s are created, they are given the next available numeric code.Digital boundary data became freely available on 1 July 2007.The 2013 Census usually resident population count, Household and Occupied dwellings (private and non-private) data has been rebased to the new 2018 meshblock pattern and is shown according to the new statistical geographies and urban rural classification developed as a result of the SSGA review. The data is experimental and is provided as a guide to understanding the impact of the new geographic boundaries on the previous census counts.Census usually resident population count: The census usually resident population count of an area is a count of all people who usually live in that area and were present in New Zealand on census night. Excluded are: visitors from overseas, visitors from elsewhere in New Zealand and residents temporarily overseas on census night. Household count: A household is either one person who usually resides alone, or two or more people who usually reside together and share facilities (such as for eating, cooking, or a living area; and bathroom and toilet) in a private dwelling. Included are people who were absent on census night but usually live in a particular dwelling and are members of that household, as long as they were reported as being absent by the reference person on the dwelling form. Occupied dwellings (private and non-private) count. For census use, a dwelling is defined as occupied if it is: occupied at midnight on the night of census data collection, or occupied at any time during the 12 hours following midnight on the night of census data collection unless the occupant(s) completed a questionnaire at another dwelling during this period. This includes occupied dilapidated dwellings and occupied dwellings under construction. Note: This data has been randomly rounded to protect confidentiality. Individual figures may not add up to totals, and values for the same data may vary in different tables.
Statistical Area 1s are based on the meshblock pattern. Non-alignment of meshblock and cadastral boundaries are one of a number of reasons for meshblock boundary adjustments. Other reasons include requests from local authorities, Local Government Commission, Electoral Representation Commission and to make census enumeration processes easier. From the meshblock pattern, higher geographies were dissolved using the dissolve tool in the Arc GIS suite.