Back to Top

 Skip navigation

Background Notes

Open in Excel:

A Census of Population was taken on the night of Sunday, 24 April 2016, in accordance with the Statistics (Census of Population) Order 20154. This report contains provisional results which are based on summaries returned by each of the 4,663 census enumerators. As these results are subject to revision they do not have any statutory force.


Coverage of the Census

The census figures in this report relate to the de facto population meaning the population recorded for each area represents the total of all persons present within that area on the night of Sunday, 24 April 2016, together with persons who arrived in the area on the morning of Monday, 25 April 2016 not having been enumerated elsewhere. Persons on board ships in port are included with the population of the area in which the ship was docked. The figures, therefore, include visitors present on Census Night as well as those in residence, while usual residents temporarily absent from the area are excluded.

The month of April is traditionally chosen for the census as it is a period when passenger movements are at a minimum; the de facto population will therefore closely approximate that of the normally resident population. Members of the Defence Forces who, on Census Night, were serving abroad with the United Nations were excluded from the enumeration.


Conduct of the Census

A temporary field force consisting of 6 Census Liaison Officers, 44 Regional Supervisors, 430 Field Supervisors and some 4,663 part-time Enumerators carried out the census enumeration. During the five weeks before Census Day enumerators delivered census questionnaires to all dwellings that were expected to be occupied on Census Night. Enumerators identified 259,562 residences that were vacant at the time of the census, while in other cases households were either enumerated elsewhere or were temporarily absent from the State. The collection of completed questionnaires took place between Monday, 25 April and Friday, 23 May, 2016.

The Central Statistics Office (CSO) wishes to record its appreciation of the high level of co-operation received from households across Ireland during the census field operation, and the hard work carried out by the census enumerators and their supervisors. 

The data in this report is based on local summary counts compiled by the 4,663 enumerators. Each enumerator summarised the total number of persons, males and females in each household onto the front of the census form and then prepared overall summary totals for their area.

These clerical summaries were returned to the CSO in advance of the census forms themselves and it is from these summaries that this Preliminary Report has been prepared. Dissemination of the definitive census results, which will include analysis of factors such as age, marital status, nationality, disability, travel patterns, industry and occupation will commence in March 2017.

The census uses the An Post Geodirectory to generate address lists for enumerators. Between 2011 and 2016 the treatment of unoccupied caravans has changed on the Geodirectory; whereas previously there was a single address point for each bay or group of mobile homes in a park, now each mobile home is listed as an individual address point. To prevent this administrative change from showing large increases in the number of holiday homes we reduced the total number of holiday homes by the number of new mobile homes/temporary dwellings added to the Geodirectory since 2011.

Vacant Dwellings

In identifying vacant dwellings, enumerators were instructed to look for signs that the dwelling was unoccupied e.g. no furniture, no cars outside, junk mail accumulating, overgrown garden etc., and to find out from neighbours whether it was vacant or not. It was not sufficient to classify a dwelling as vacant after one or two visits. Similar precautions were also taken when classifying holiday homes.

Dwellings under construction and derelict properties are not included in the count of vacant dwellings. In order to be classified as under construction, the dwelling had to be unfit for habitation because the roof, doors, windows or walls had not yet been built or installed.


Administrative & Census Areas

There are many different geographic divisions of the country. Those used in the 2016 Census of Population are described below. All the areas are as defined at the date of the census.

Small Areas

The enumeration of Census 2016 was organised using Small Areas, which are a new administrative unit developed by the National Institute for Regional and Spatial Analysis (NIRSA) at the behest of Ordnance Survey Ireland (OSi) and in collaboration with the CSO. There are approximately 19,000 Small Areas containing, on average, between 75‐150 households. The Small Areas nest within existing Electoral Divisions. Each enumerator was assigned an area averaging 420 dwellings consisting of 3-4 Small Areas.

Electoral Divisions (EDs)

The smallest administrative area for which population statistics are provided in this report is the Electoral Division (formerly called District Electoral Division). There are 3,441 Electoral Divisions in the State and their populations are available in the statbank on the CSO website, table EP008.

Counties and Cities

The results in this report are provided for the 34 administrative areas, consisting of 29 counties and five cities, that existed prior to the Local Government Reform Act 2014. In Dublin four areas are identified separately, namely Dublin City, Dún Laoghaire-Rathdown, Fingal and South Dublin. Outside of Dublin results are provided for 26 administrative counties (including North Tipperary and South Tipperary separately) and the four cities of Cork, Limerick, Waterford and Galway.

The boundaries of the cities are subject to periodic extensions to keep pace with building development and it is not possible, therefore, to show comparable retrospective population figures over an extended period. Counties, on the other hand, have only been affected to a very minor extent by boundary changes and it is possible to compare county populations (including the appropriate cities) over a long period of time. This is done in table EP002 in statbank, which shows county population figures for each census year from 1926 to 2016.

Dáil Constituencies

For the purpose of elections to Dáil Éireann the country is divided into constituencies which, under Article 16.4 of the Constitution of Ireland, have to be revised at least once every twelve years with due regard to changes in the distribution of the population. The constituencies were last revised in 2013 and the Schedule to the Electoral (Amendment) (No.7) Act 2013 contains details of their composition. The 2016 population figures for these areas are given in table EP003 in statbank.


All maps in this release are © Ordnance Survey Ireland. All rights reserved. License number 01/05/001.

Regional Authorities (NUTS3 Regions)

The geographical sub-divisions used in table EP004 in statbank are based on Regional Authorities. These eight regions were established under the Local Government Act 1991, Regional Authorities Establishment Order 1993 which came into operation on 1 January 1994.

Regional Authorities (NUTS3 Regions)

4 The Statistics (Census of Population) Order 2015 was made by the Taoiseach in pursuance of powers conferred on him by section 25 (1) of the Statistics Act 1993 ( No. 21 of 1993).

Why you can Trust the CSO

Learn about our data and confidentiality safeguards, and the steps we take to produce statistics that can be trusted by all.