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Background Notes

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Appendix 1

Background Notes

A Census of Population was taken on the night of Sunday, 24 April 2016, in accordance with the Statistics (Census of Population) Order 2015 (S.I. No. 445 of 2015)[1]

Coverage of the Census

The census figures relate to the de facto population i.e. the population recorded for each area represents the total of all persons present within its boundaries on the night of Sunday, 24 April 2016, together with all persons who arrived in that 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 adjacent areas. 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.

De facto versus Usual Residence

The date of the census was chosen to coincide with a period when passenger movements were at a minimum and, consequently, the figures closely approximate to those for the normally resident population. The de facto measure of the population, referred to throughout this report, was 4,761,865 in April 2016 while the usually resident and present total was 4,689,921, a difference of 71,944 or 1.5%. The usually resident measure is used when analysing topics such as nationality and households and families.

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 four weeks before Census Night the enumerators visited some 2 million private residences and delivered census questionnaires to 1.7 million of these dwellings as well as to 4,140 communal establishments capable of accommodating people (such as hotels, nursing homes, etc,) that were expected to be occupied on census night. Approximately 250,000 residences were vacant at the time of the census, while in the remaining cases the household was either enumerated elsewhere or temporarily absent from the State. The collection of completed questionnaires took place between Monday 25 April and Sunday 22 May, 2016.

The Central Statistics Office (CSO) wishes to record its appreciation of the public-spirited co-operation received from households and the work carried out by the census field force.

Production of results

Each enumerator first prepared and returned to the CSO a summary of the population of his/her enumeration area. These summaries formed the basis for the preliminary 2016 census results published in July 2016. The completed questionnaires for individual households were subsequently transported to the CSO for processing. The population summaries, dwelling listings and enumeration maps for individual enumeration areas were checked for consistency and used to determine the boundaries of census towns and suburbs. The capture and processing of the responses to questions on the questionnaires proceeded concurrently.

The planned publication schedule is contained in Appendix 3. Two summary reports will present highlight results primarily for the State; Census 2016 Summary Results - Part 1, looks at overall population change by county; it also examines age, marriage, households and families as well as including first results on nationality, foreign languages, the Irish language, religion and housing. The second summary report, Census 2016 Summary Results - Part 2, will look at other social and economic factors such as employment, occupations, education and skills as well as travel and health-related topics. A further nine profile reports will provide more detailed results on individual topics; the details are listed in the publication schedule.


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

Further information 

For further information contact:

Census Enquiries Section, Central Statistics Office , Swords Business Campus, Balheary Road, Swords, Co. Dublin

Phone(01) 8951460  

LoCall 1890 236 787        

Fax    (01) 895 1399 




Appendix 2

Census Geographic Definitions


There are many different territorial divisions of the country used in the Census. The most important of these are defined below using the definitions as they existed on the 24th April 2016.

Small Areas(SAs)

Small Areas are a relatively recent geographic concept compiled by the National Institute of Regional and Spatial Analysis (NIRSA) on behalf of the Ordnance Survey Ireland (OSi) and in consultation with the CSO. They were designed as the lowest level of geography for the compilation of statistics in line with data protection guidelines and typically contain between 50 and 200 dwellings. A further constraint imposed when creating these new areas, was that they nested within Electoral Division boundaries. Finally, they are generally comprised either of complete townlands or neighbourhoods.

Population data for the 18,641 small areas identified from Census 2016 is available here.

Electoral Divisions (EDs) 

Electoral Divisions are the smallest legally defined administrative areas in the state.

Previously, known as District Electoral Divisions[1](DEDs) began as subdivisions of poor law unions, grouping one or more townlands together to elect members to a Board of Guardians. The DED boundaries were drawn by a Poor Law Boundary Commission, with the intention of producing areas of roughly equal "rateable value" as well as population. EDs are mostly contiguous but may bear little relation to natural community boundaries.

There are 3,440 legally defined EDs in the State. One ED, St. Mary's, straddles the Louth-Meath county border, and is presented in two parts in this publication split along the county border.  For the purposes of detailed ED Small Area Population tables (SAPs), 32 EDs with a low population have been amalgamated with neighbouring EDs for disclosure reasons giving the total of 3409 EDs which will appear in the SAPS tables later in 2017.

Urban and Rural Districts

Urban and Rural Districts have been superseded by Municipal Districts under the Local Government Reform Act, 2014.

For historical comparison, population figures for Urban and Rural Districts are given in Table 4.1.

Census 2016 Profile 2 Population Distribution and Movements Table 4.1 (XLS 236KB)

Counties and Cities

Under the Local Government Reform Act, 2001 (S.I. 591 OF 2001) the areas formerly known as County Boroughs are now called Cities.  Areas formally known as Municipal Boroughs are now called Boroughs.                                   

The Local Government Reform Act 2014 Section 9 provided for the amalgamation of the city and county councils in Limerick and Waterford, and North Tipperary and South Tipperary County Councils. The newly amalgamated councils will be called Limerick City and County Council, Tipperary County Council and Waterford City and County Council.

In census reports, the country is divided into 26 Counties/administrative counties and the five Cities.  Outside Dublin, there are 23 administrative counties and four Cities, i.e. Cork, Limerick, Waterford and Galway.  In Dublin, the four local authority areas are identified separately, i.e. Dublin City and the three Administrative Counties of Dún Laoghaire-Rathdown, Fingal and South Dublin.

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 E2001, which shows county population figures for each census year from 1841 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 Tables EY003, E2015 and E2017. 

Local Electoral Areas and Municipal Districts

For the purposes of County Council and Corporation elections, each county and city is divided into Local Electoral Areas (LEAs) which are constituted on the basis of Orders made under the Local Government Act, 1941.  In general, LEAs are formed by aggregating Electoral Divisions.  However, in a number of cases, Electoral Divisions are divided between LEAs to facilitate electors.  Population figures for Local Electoral Areas are given in Table E2018. Statutory Instruments No’s 40-70 /2014 state the current composition of LEA’s and their subsequent amalgamation into Municipal Districts. (See Table E2019.)

Legal and Census Towns 

80 Legal Town boundaries were abolished under the Local Government Reform Act 2014.

Census Towns

Historically, for the censuses of 1926 to 1951, a census town was defined simply as a cluster of twenty or more houses and the precise delimitation of the town was left to the discretion of the individual enumerator concerned. As part of the general review of towns for the 1956 Census, the boundaries for the census towns were drawn up in consultation with the various Local Authorities applying uniform principles in all areas of the country. The definition of a census town was changed at the 1956 Census, from twenty houses to twenty occupied houses; this definition was also applied at the 1961 and 1966 Censuses.

From 1971 to 2006, Census towns were defined as a cluster of fifty or more occupied dwellings where, within a radius of 800 metres there was a nucleus of thirty occupied dwellings (on both sides of a road, or twenty on one side of a road), along with a clearly defined urban centre e.g. a shop, a school, a place of worship or a community centre. Census town boundaries were extended over time where there was an occupied dwelling within 200 metres of the existing boundary.

To avoid the agglomeration of adjacent towns caused by the inclusion of low density one off dwellings on the approach routes to towns the 2011 criteria were tightened, in line with UN criteria.

In Census 2016, a new Census town was defined as there being a minimum of 50 occupied dwellings, with a maximum distance between any dwelling and the building closest to it, of 100 metres, and where there was evidence of an urban centre (shop, school etc). The proximity criteria for extending existing 2006 Census town boundaries was also amended to include all occupied dwellings within 100 metres of an existing building. Other information based on OSi mapping and orthogonal photography was also taken into account when extending boundaries. Boundary extensions were generally made to include the land parcel on which a dwelling was built or using other physical features such as roads, paths etc.

Census towns which previously combined legal towns and their environs have been newly defined using the standard census town criteria (with the 100 metres proximity rule). For some towns the impact of this has been to lose area and population, compared with previous computations.

The population of towns is given in Tables E2014 and E2016. Table E2014 contains towns of 1,500 population and over arranged in order of size. An alphabetical list of all towns in the country, with their populations, is given in Table E2016.

New Census Towns

26 new census towns were created for the 2016 Census.





















Baile an Droichid



New Twopothouse



Aggregate Town and Aggregate Rural Areas

The term Aggregate Town Area (Tables E2004, E2009 & E2032) refers to towns with a total population of 1,500 or more.  The term Aggregate Rural Area refers to the population outside Aggregate Town areas and includes the population of towns with a population of less than 1,500 persons.

Gaeltacht Areas

The Gaeltacht Areas Orders, 1956, 1967, 1974 and 1982 defined the Gaeltacht as comprising 155 Electoral Divisions or parts of Electoral Divisions in the counties of Cork, Donegal, Galway, Kerry, Mayo, Meath and Waterford.  The population of these Electoral Divisions or parts thereof in 2011 and 2016 is given in Table E2020.

The 2012 Gaeltacht Act defined 26 distinct language planning areas within the Gaeltacht and figures are found in Table E2046.

Islands off the Coast

The population in 2011 and 2016 of inhabited islands off the coast is shown in Table E2021.  In some cases the areas of land concerned may not, strictly speaking, be considered as islands since they are connected to the mainland by a causeway or bridge, or may be reached by land at low tide.  However, they have been retained unchanged in the present publication in order to provide continuity with previous censuses.

GIS and digital boundaries for Census 2016

Due to changes to the fieldwork methodology for Census 2011 and continued in Census 2016, each household and dwelling was linked to geographical coordinates (i.e. latitude and longitude or GPS coordinates). This linkage has the benefit of offering flexibility in the production of Census 2016 outputs for both existing and new boundaries provided they are available in digital format.

The boundaries for the various geographical areas referenced in this report have been digitised by Ordnance Survey Ireland (OSi). The exceptions to this were the boundaries of towns or Settlements, which were digitised by the CSO. The Census 2016 data was then geographically coded using these digital boundaries and a Geographical Information System (GIS).

Digital boundaries are available on as vector files in ESRI shape (SHP) format for 18,641 Small Areas and 3,409 EDs along with their administrative counties. The boundaries have been smoothed in accordance with our licensing agreement with OSi. These boundaries are for general information and are not accurate enough for use in data geocoding. Any individual or organisation who wishes to download the boundaries must acknowledge the terms and conditions under which they are made available.

Area Measurement and Population Density

The measurement of area in square kilometres is shown in Table E2013 and E2014. The base data for area calculation was provided by Ordnance Survey Ireland. The areas shown are exclusive of water bodies such as large rivers, lakes, estuaries, ponds and reservoirs. Population density is calculated as total persons divided by number of square kilometres.

Regional Authorities

The Nomenclature of Territorial Units for Statistics (NUTS) were drawn up by Eurostat in order to define territorial units for the production of regional statistics across the European Union. The NUTS classification has been used in EU legislation since 1988, but it was only in 2003 that the EU Member States, the European Parliament and the Commission established the NUTS regions within a legal framework (Regulation (EC) No 1059/2003).

Revisions were made to the NUTS boundaries in 2016 and were given legal status under Commission Regulation (EU) 2016/2066 amending annexes to NUTS Regulation 1059/2003. Population figures for regional authorities are given in Table E2009.

[1] The term District Electoral Division was changed to Electoral Division by Section 23 of the Local Government Act, 1994 with effect from 24 June 1996 (S.I. 196 of 1996 refers).


Appendix 3

Census 2016 Publication Schedule                                                                           

Description                                        Publication Date
Preliminary Results                                 14 July 2016
Census 2016 Summary Results - Part 1               06 April 2017
Profile 1 - Housing in Ireland                     20 April 2017
Profile 2 - Population Distribution and Movements   11 May 2017
Census 2016 Summary Results - Part 2               15 June 2017
Profile 3 - An Age Profile of Ireland               06 July 2017
Small Area Population Statistics (SAPS)           20 July 2017
POWSCAR - Research micro data file                 20 July 2017
Profile 4 - Households and Families                 27 July 2017
Profile 5 - Homeless Persons in Ireland             10 August 2017
Profile 6 - Commuting in Ireland                   31 August 2017
Profile 7 - Migration and Diversity                 21 September 2017
Profile 8 - Irish Travellers, Ethnicity and Religion 12 October 2017
Profile 9 - Health, Disability and Carers         02 November 2017
Profile 10 - Education, Skills and the Irish Language 23 November 2017
Profile 11 - Employment, Occupations and Industry   14 December 2017


Interactive web tables will accompany each publication