ONS Coding System - Geography of The UK Census

Geography of The UK Census

Information from the 2001 Census is published for a wide variety of geographical units, and a similar approach will be taken for the 2011 Census. These areas include:

• Counties in England
• Districts within English counties, and Unitary Authority areas served by one council providing district and county functions
• Unitary council areas in Wales, Scotland, and Northern Ireland
• Civil parishes (communities in Wales)
• Electoral wards (called electoral divisions in Wales). These are the areas defined for the election of local councillors, but are also widely used for presenting statistics at a smaller scale than the whole district.
• Census output areas. These are the smallest unit for which census data are published - they were initially generated to support publication of Census 2001 outputs and contain at least 40 households and 100 persons, the target size being 125 households. They were built up from postcode blocks after the census data were available, with the intention of standardising population sizes, geographical shape and social homogeneity (in terms of dwelling types and housing tenure). The output areas generated in 2001 will retained as far as possible for the publication of outputs from the 2011 census. Prior to 2001, census data were published for larger Enumeration Districts which were delineated before the census was conducted and were the organizational units for census data collection.