Harmonisation of boundaries
The division of England and Wales into Output Areas was completed in late January 2003. The release of the Output Area boundaries was later than planned, although in time for preparations before release of the local statistics. The main change in the timing of the production of Output Areas was to allow compliance with a new National Statistics policy to harmonize output to boundaries as they exist at the end of each calendar year. The Output Area boundaries were therefore produced to fit the ward and parish/community boundaries legally in place on 31 December 2002, with production continuing into January 2003. This also met the very widesperead customer demand for output for up to date areas.
The availability of the Output Area boundaries was also delayed by an additional month to allow a limited number of changes and corrections after quality assurance. Perhaps the most significant is that the 'extent of the realm', which includes areas of sea and which was used in the production of Output Areas, has been retained as the containing outer boundary of the Output Areas in preference to mean high water mark. This avoids some splitting of coastal Output Areas into two or more parts, but area measurements for coastal Output Areas are for the part above mean high water mark to avoid distortion in density calculations.
Number of Output Areas
There are some 175,434 Output Areas in England and Wales. Some 37.5% lie between 120 and 129 households, whilst 79.6% lie between 110 and 139 households. Some 5% lie between 40 households - the confidentiality threshold - and 99 households, and many of these are single parishes (or Communities in Wales). The distribution of size by households has a single sharp peak, showing a consistency in size compared with the number of peaks which appeared in the distribution of 1991 Census Enumeration Districts by size.
The number of Output Areas in each authority, together with information on the operative dates for the district, ward and parish boundaries in each authority is available HERE (as an Excel file).
The authorities are arranged on the Excel spreadsheet as viewed initially in the standard order for presentation of statistics: Greater London; Metropolitan areas; Unitary Authorities in England (Government Office Region order); Unitary Authorities in Wales (North to South geographical order); Counties in England (alphabetical order). Where no operative date is shown for an authority, boundaries used in the creation of Output Areas are as at Census Day (29.04.01).
Census News
