This dataset shows the 2001 Census Output Areas (OAs). OAs are the smallest geographical unit for which Census data is released, and as a result, they act as the basic “building-blocks” for the creation of other “higher” geographies, eg Datazones, council areas. The OAs are constructed by aggregating together a small number of postcodes. Because the OAs cover small areas and contain relatively small numbers of households and population (households in the range 20 to 77; population >/= 50), there is only a limited amount of Census data that can be released without infringing confidentiality. Each OA is assigned to an area in a ‘higher’ geography by first selecting one of the postcodes in the OA as a ‘master’ postcode. The OA inherits all the characteristics of the master postcode including its assignment to higher areas and its centroid grid reference. The master postcode is the postcode with the grid reference closest to the centre of the OA weighted by census household. There are 42,604 Census 2001 OAs in Scotland.

This dataset portrays the boundaries of ‘Localities’ in Scotland as at the 1991 Census.. There is widespread interest in statistics for the built-up areas in Scotland as most of the population lives in a built-up environment. When the former two-tier local government structure of regions and districts came into being in May 1975, the small local authorities known as large and small burghs were lost. However, Census users stated that there was a need to know the population (and characteristics) of built-up areas. For 1991 Localities, information on the area of a postcode was available from the digitised postcode boundaries and also on the postcode’s population from the 1991 Census. The method used to identify localities in 1991 was basically to classify a postcode as either urban or rural based on population density. Groups of urban (high population density) postcodes were identified where the number of residents in all the postcodes in the group was 500 or more. The final stage was to ask the local authorities to suggest any changes which might refine the boundaries of the identified settlements. This method identified 603 localities, 448 of which contained 1,000 residents or more, with the remainder containing a population of 500 or more but less that 1000.

The 8 old operational areas in Highland (pre 2007): Badenoch and Strathspey; Caithness; Inverness; Lochaber; Nairn; Ross and Cromarty; Skye and Lochalsh; Sutherland;

This dataset portrays the boundaries of ‘Localities’ in Scotland as at the 2001 Census.. There is widespread interest in statistics for the built-up areas in Scotland as most of the population lives in a built-up environment. When the former two-tier local government structure of regions and districts came into being in May 1975, the small local authorities known as large and small burghs were lost. However, Census users stated that there was a need to know the population (and characteristics) of built-up areas. For the 2001 Census the method used to identify Localities was very similar to that used in 1991 in that it was based on identifying groups of high density postcodes.

This dataset shows the 2011 Census Output Areas (OAs) Population Weighted Centroids. An individual Output Area generally covers a sufficiently small area (subject to meeting minimum population / household counts) so that user defined or ad-hoc areas can be created while maintaining a sufficient level of quality. National Records of Scotland (NRS) produces only one set of OAs and creates all other output geographies using the OA as the building brick. Each OA is assigned to an area in a higher geography by first selecting one of the postcodes in the OA as a ‘master’ postcode. The OA inherits all of the characteristics of the master postcode including its assignments to higher areas and its grid reference. The master postcode was selected using an algorithm which calculates the postcode centroid within an OA which has grid references closest to the population-weighted centre of the OA. An anomaly was discovered in the 2011 Census Output Area (OA) codes which were published on 15 August 2013. The anomaly meant that, whilst all the current 2011 Census OA codes were unique, they did not always run in sequential order by council area. We decided to replace the codes with new ones that start at S00088956 and end with S00135306.

NRS first created Output Areas (OAs) for the 1991 Census to allow comparability with small area statistics output from 1971 and 1981. NRS used postcodes to plan 1981 Census enumeration districts and 1991 postcode based OA generally fell within 1981 ED. 1971 small area statistics were retabulated for 1981 Enumeration Districts thus provided an degree on continuity over 3 censuses. OAs are the lowest level for which small area statistics for the 1991 Census are available. For confidentiality purposes each OA has at least 16 households and 50 usual residents. There are 38,254 Census 1991 OAs in Scotland. Of the 38,254 1991 output areas, 38,098 have polygons, the remaining 156 are special output areas. Revisions and Corrections Correction to 1991 Output Area boundaries An anomaly was discovered in the 1991 Output Area boundaries where the boundaries for Output Areas 6341DX13 and 6341DX16B were not following the postcodes that they were built up from.

A 2001 Census Area Statistic (CAS) ward is one of 2 special wards created for 2001 Census Output. These are both created by aggregating output areas and are only best-fit for electoral wards. Using master postcodes, OAs are assigned to electoral wards. The resulting 1,222 aggregations are denoted CAS wards and will fall within a council area boundary and meet a threshold of 20 households and 50 persons.

This is the set of postcode boundaries used for 2011 census outputs. The postcode boundaries for census were originally frozen in January 2011 but have since been re-aligned to Ordnance Survey 2011 BoundaryLine for the purposes of producing census outputs. The re-alignment work ensures consistency of approach with the Office of National Statistics (ONS) and the Scottish Government (SG). The improvements made to the dataset as a result of re-alignment did not affect any existing higher area assignments in the Postcode Index although there will be some very minor differences in the boundaries if compared against the 2011_1 set of postcode boundaries already published. The dataset contains 145,690 postcode polygons. Revisions and Corrections Revision to postcode boundaries at boundary between East Renfrewshire and Renfrewshire Council areas (7 October 2013) Postcodes PA2 7DA, PA2 7TX, PA2 8TY, G53 7TH, G78 1HJ, and G78 1TJ have been amended following a correction to Ordnance Survey BoundaryLine.

This dataset shows the 2011 Census Output Areas (OAs) – Part Removed. This dataset contains the polygons which were removed in order to make the OA whole. The area of these polygons is included in the area figure for the 2011 OA. There were 349 non contiguous census output areas not caused by water. A decision was made to delete one of the polygons to make the OA whole. This was purely a cosmetic exercise. The part to be removed did not contain the master postcode and in the majority of the cases it was the smaller of the polygons but in a few instances it may have been the large part simply because the smaller part was more dense and master postcode assigned to it. Revisions and Corrections Revision to 2011 Output Area codes (13 September 2013) An anomaly was discovered in the 2011 Census Output Area (OA) codes which were published on 15 August 2013. The anomaly meant that, whilst all the current 2011 Census OA codes were unique, they did not always run in sequential order by council area. We decided to replace the codes with new ones that start at S00088956 and end with S00135306. Correction to 2011 Output Area boundaries (7 October 2013) Ten boundaries have been added to the dataset following amendments in line with the cosmetic exercise/spatial improvement described earlier