This code creates lookup tables between historic small area geographies and modern geographies, so that it is possible to aggregate historic small area Census data to larger modern boundaries. The modern boundaries currently of interest (as part of the LNRI project) are 2011 Travel to Work Areas and 2021 local authority districts for Great Britain.
The small areas depend upon the Census year, as they have changed over time
A single .zip file with small area statistics data is available for each of the 1971, 1981, 1991, 1981 and 2001 Censuses from the UK Data Service. These are not always as helpful as they could be, as they come with minimal (or no!) documentation, and understanding what the tables refer to often requires referring to the small area statistics tables on Nomis (at the time of writing I think this service is under development so it may improve).
There are legacy UKDS services at Casweb and InFuse.
Historic boundary datasets for the UK Censuses from 1971 onwards are available from the UK Borders service (not all boundaries are available as 'easy download' - see the 'boundary data selector' for all available boundaries); more recent boundary sets are available from the ONS geography portal.
- England & Wales: electoral wards used for small area statistics (area code example 01AAAA)
- Scotland: ward equivalent is postcode sectors, see guidance on NRS website (area code example 6554AC)
- total of 10,445 wards and postcode sectors on land - 'shipping' geographic codes were also included to count people not present on land at the time of the Census. These codes all end in 'SS' (e.g. 01AASS). Including these shipping codes there are 10,903 small areas
Below this level there are enumeration districts for Scotland (e.g. 5601AB03) and England & Wales (e.g. 01AAAA01).
Full small area datasets with Great Britain data combined are available from UK Data Service bulk download. Hierarchy number 3 has wards for England & Wales and postcode sectors for Scotland; hierarchy number 4 has enumeration districts.
Shapefiles are available from UK Borders website. Dataset listed as Scottish Wards is actually postcode sectors.
- England & Wales: use wards for small area statistics (area code example 17FEFL)
- Scotland: ward equivalent is postcode sectors, see guidance on NRS website (area code example 6123AL)
- total of 10,528 wards and postcode sectors, excluding 'SS' shipping codes and lochs (the latter are included in the Scottish postcode sector shapefile)
Full small area datasets with Great Britain data combined are available from UK Data Service bulk download. Hierarchy number 3 has wards for England & Wales and postcode sectors for Scotland; hierarchy number 4 has enumeration districts for England & Wales and Output Areas for Scotland.
Boundaries are available from UK Borders service, however it is tricky to find the right ones. For England, it is electoral wards which is straightforward. For Wales it is also electoral wards but the standard boundary dataset is incomplete - the one listed as 'super generalised' is complete. For Scotland you need to find the 'pseudo postcode sectors'. One of the areas in the Scotland dataset is mislabelled, see code for details.
This is the first year of the modern Data Zone / Output Area hierarchy of small areas, with a statistical (rather than electoral or administrative) geography covering the whole of Britain.
- England & Wales: output areas (OAs), lower super output areas (LSOAs), middle super output areas (LSOAs). My preference is to work with LSOAs
- Scotland: Data Zones (DZs) and Intermediate Zones (IZs). My preference is to work with DZs.
LSOA data is available in the 2001 Census bulk data download from the UK Data Service, or from NOMIS. In the UKDS bulk data file, the LSOA data is in the files starting with "s" e.g. "s01ks09a_ons.csv"
DZ data is available as a bulk download zip file from the National Records of Scotland (it is not available via UKDS or Nomis).
Boundaries for 2001 Data Zones and LSOAs are readily available.
The small area hierarchy has the same structure as in 2001, but updated sets of the geographies were produced (i.e. there are separate 2001 and 2001 versions of LSOAs, etc).
Small area data for the whole UK is available from Nomis.
Boundaries for 2011 Data Zones and LSOAs are readily available including from the ONS Open Geography Portal.