Census 2011 was the first time where each household and dwelling was linked to spatial coordinates, thereby offering greater flexibility in relation to the production of geographical outputs. The result of this linkage means that grid cells of equal size can be used to disseminate data from the 2011 census. The advantages of grids are that they offer independence from existing administrative boundaries (which can facilitate cross-border analysis) and provide a better representation of the spatial distribution of the population.
Following consultation with a limited number of users of census data in Ireland, and in order to fulfil our commitments to the European Forum of GeoStatistics (EFGS), data from the 2011 census has been aggregated into 1 km² grid cells and made available as a free product for public access. This dataset includes the total population of persons usually resident in the Republic of Ireland on April 10th 2011 (census night), classified by sex and broad age groups.
Certain grid cell values have been suppressed in order to protect against the disclosure of data which could identify the attributes of an individual person or household. For grid cells which have less than three households, the total population variable has been altered and contains a value of ‘4’ or ‘5’. In the case of the age or sex variables which breached our rules of confidentiality, the data in those cells have been suppressed and therefore contains a value of ‘-1’. Following the implementation of these rules, 19.4% of all cells in the dataset have been suppressed.
The 1 Km² grid dataset is available in the Irish Transverse Mercator (EPSG Code 2157) as a comma delimited values file (.csv) and in vector format (.shp). It is also available in the ETRS89 Lambert Azimuthal Equal-Area (EPSG Code 3035) projection on request.
Further information is available in the pdf document below.