Many statistics we collect use geographic areas to classify data. A meshblock is the smallest geographic area used to collect and present statistics. Meshblocks are aggregated to form larger geographic areas, such as area units, urban areas, territorial authorities, and regional councils.
A meshblock is a flexible building-block geography. Its size depends mainly on the number of dwellings it contains and the type of land it covers. At the 2013 Census there were 46,637 meshblocks and 2,020 area units in New Zealand.
The diagram below illustrates Statistics NZ’s geographic hierarchy.
When we create a meshblock, it is allocated a unique seven-digit number. A meshblock’s boundaries usually align to cadastral or physical features that are obvious on the ground. Maintenance of meshblocks is ongoing and includes splitting or nudging their boundaries. Each year, we archive the meshblock pattern and create a concordance to ensure we maintain the relationships to earlier meshblock patterns.
We change meshblock boundaries for many reasons, including:
- communities of interest
- changing cadastral patterns
- size of meshblock – number of dwellings preferably between 30 and 60
- physical access to properties
- physical size and shape of meshblock, for ease of enumeration
- distinguishing between residential, commercial, and industrial areas
- recognisable boundaries, such as rivers and motorways
- keeping large complexes, such as retirement homes and hospitals, within a single meshblock
- keeping environmentally sensitive areas together
- requests from external customers, such as central/local government and other organisations
- requests from internal data users, such as census (for enumeration).
When altering meshblocks, we must consider a number of criteria, for example, legally defined boundaries such as regional council, territorial authority, ward, and general and Māori electoral districts. We work closely with the Electoral Representation Commission, Local Government Commission, territorial authorities, regional councils, and district health boards during boundary revision exercises to ensure meshblock boundaries are suitably located for electoral purposes.
Updated 29 October 2015