Analysis unit

Persons and households

UNITS IDENTIFIED: - Dwellings: no - Vacant Units: no - Households: yes - Individuals: yes - Group quarters: no

UNIT DESCRIPTIONS: - Dwellings: A dwelling has a distinct outer door and shall be considered as one house, although it may be occupied by several families living in separate apartments, or what are known as tenements, under the same roof. - Households: A "distinct family" is defined as (a) a man and his wife or a man and his and children living together, and no other person residing with them or family such as either of the foregoing, with their relatives, servants, and visitors residing with them. (b) All persons occupying the same house common and boarding at the same table, and their servants. (c) A person living alone whether occupying the whole or a part of a house, with servants, if any. (d) Two or more lodgers boarding together distinct from the family and their servants, if any. - Group quarters: A non-private household is a boarding house, hotel, guest house, barrack, hospital, nursing home, boarding schools, religious institution, welfare institution, prison, or ship, etc.

Universe

All persons present in Ireland at the time of census, including visitors and those in residence.

Kind of data

Population and Housing Census [hh/popcen]

Sampling procedure

MICRODATA SOURCE: The National Archives of Ireland

SAMPLE SIZE (person records): 4381387.

SAMPLE DESIGN: Full count

Mode of data collection

Face-to-face [f2f]

Research instrument

The information is based on Form A- Household Schedule. Form B reports summary tables of population figures.

This dataset provides Census 2021 estimates that classify usual residents in Northern Ireland by sex. The estimates are as at census day, 21 March 2021.

The census collected information on the usually resident population of Northern Ireland on census day (21 March 2021). Initial contact letters or questionnaire packs were delivered to every household and communal establishment, and residents were asked to complete online or return the questionnaire with information as correct on census day. Special arrangements were made to enumerate special groups such as students, members of the Travellers Community, HM Forces personnel etc. The Census Coverage Survey (an independent doorstep survey) followed between 12 May and 29 June 2021 and was used to adjust the census counts for under-enumeration.

This dataset provides Census 2021 estimates that classify usual residents in Northern Ireland by their national identity (person based). The estimates are as at census day, 21 March 2021. The national identity classification used is an 8-category classification corresponding to selected tick box options on the census questionnaire. This dataset is mutually exclusive; respondents are included in one group only (for example, this classification includes a 'British only' group, 'Irish only' group, and 'British and Irish only' group).

The census collected information on the usually resident population of Northern Ireland on census day (21 March 2021). Initial contact letters or questionnaire packs were delivered to every household and communal establishment, and residents were asked to complete online or return the questionnaire with information as correct on census day. Special arrangements were made to enumerate special groups such as students, members of the Travellers Community, HM Forces personnel etc. The Census Coverage Survey (an independent doorstep survey) followed between 12 May and 29 June 2021 and was used to adjust the census counts for under-enumeration.

IPUMS-International is an effort to inventory, preserve, harmonize, and disseminate census microdata from around the world. The project has collected the world's largest archive of publicly available census samples. The data are coded and documented consistently across countries and over time to facillitate comparative research. IPUMS-International makes these data available to qualified researchers free of charge through a web dissemination system. The IPUMS project is a collaboration of the Minnesota Population Center, National Statistical Offices, and international data archives. Major funding is provided by the U.S. National Science Foundation and the Demographic and Behavioral Sciences Branch of the National Institute of Child Health and Human Development. Additional support is provided by the University of Minnesota Office of the Vice President for Research, the Minnesota Population Center, and Sun Microsystems.

These statistics contain the first phase of main statistics results from Census 2021. This phase provides estimates for a number of census topics, including passports held, ethnic group, national identity, language, and religion.

Data are available for Northern Ireland and the 11 Local Government Districts.

Workplace Zones (WZs) are a new output geography, initially produced using workplace data from the 2011 Census for England and Wales rather than the UK as a whole. They are designed to supplement the Output Area (OA) and Super Output Area (LSOA and MSOA) geographies that were introduced with the 2001 Census, and have been constructed from OAs, or sub-divisions of these called postcode-level building-blocks (PCBBs). While OAs are designed to contain consistent numbers of persons based on where they live, WZs are designed to contain consistent numbers of workers, based on where people work. Following publication of WZs for England and Wales, coverage has subsequently been extended to include Scotland and Northern Ireland using 2011 Census data to create a UK set of WZs produced by the Office for National Statistics (ONS) on behalf of National Records of Scotland (NRS) and the Northern Ireland Statistics and Research Agency (NISRA). WZs are designed to be a more suitable output geography for publishing workplace statistics.

These statistics contain the first phase of main statistics results from Census 2021. This phase provides estimates for a number of census topics, including passports held, ethnic group, national identity, language, and religion.

Data are available for Northern Ireland and the 11 Local Government Districts.

Every ten years since 1801 the nation has set aside one day for the census - a count of all people and households. It is the most complete source of information about the population that we have. The latest census was held on Sunday 27 March 2011.

Every effort is made to include everyone, and that is why the census is so important. It is the only survey which provides a detailed picture of the entire population, and is unique because it covers everyone at the same time and asks the same core questions everywhere. This makes it easy to compare different parts of the country.

The information the census provides allows central and local government, health authorities and many other organisations to target their resources more effectively and to plan housing, education, health and transport services for years to come.

In England and Wales, the census is planned and carried out by the Office for National Statistics. Elsewhere in the UK, responsibility lies with the National Records of Scotland and the Northern Ireland Statistics and Research Agency.

All 2011 Census data for ‘Welsh’ records are defined as those: - Currently resident in Wales - With a second address in Wales - With a previous Years Address in Wales - With a term-time address in Wales - Who work in Wales (but live in England) - In Armed Forces Establishments in Wales - Who are visitors in Wales - Who are Welsh language speakers (including those who live and work outside of Wales).

The ONS have three processes for checking and resolving duplicate responses so that the main census data should simply be one record for each person:

1. The ONS resolve duplicates coming in for the same postcode using a process called Resolve Multiple Responses (RMR). For instance, if two people both fill in a form for their whole household, or someone from a household also submits an individual response unknown to the main submission. They have rules for checking they are duplicates, and rules for which to keep.

2. The ONS also do an over coverage check on a sample basis for duplicates across the rest of the country, and then factor the findings into their coverage estimation calculations. This sampling focuses on the types of population which are more likely to be duplicated (people who have indicated they have a second residence on the census, students aged 18-25, armed forces personnel, children, adults enumerated at a communal establishment, etc.) but also samples from the remaining population.

3. The ONS ask parents to fill in basic demographic information for any children who are away studying, and when they get to the question on their term-time address, if they answer that the term-time address is elsewhere, we then use that to filter those out-of-term students out of the main database. Then when that student does respond actually at their term-time address, they only include them there.

Please note: Variables RELAT06, RELAT11, RELAT16, RELAT21, RELAT26 are not available in the data.

The Research Accreditation Panel provides oversight of the framework that is used to accredit research projects, researchers and processing environments under the Digital Economy Act 2017 (DEA). Researchers are advised to liaise with SAIL support teams to understand the requirements and timelines involved with submitting a research project to the Research Accreditation Panel. https://uksa.statisticsauthority.gov.uk/digitaleconomyact-research-statistics/research-accreditation-panel/

The UK censuses took place on 27 March 2011. They were run by the Northern Ireland Statistics & Research Agency (NISRA), National Records of Scotland (NRS), and the Office for National Statistics (ONS) for both England and Wales. The UK comprises the countries of England, Wales, Scotland and Northern Ireland.Statistics from the UK censuses help paint a picture of the nation and how we live. They provide a detailed snapshot of the population and its characteristics and underpin funding allocation to provide public services. This is the home for all UK census data. The 2011 Census Microdata Individual Safeguarded Sample (Local Authority): Northern Ireland data collection forms part of the statistical outputs from the 2011 Northern Ireland Census. A safeguarded microdata sample of individuals has been identified as a key Census user requirement, and was highlighted as part of a report specifying microdata products from the 2011 Census written by an expert user, Dr. Jo Wathan from the University of Manchester.

The purpose of a safeguarded sample of individuals is to be able to disseminate a detailed microdata file without onerous licensing conditions, by reducing the overall amount of detail compared to the secure samples. Whilst supplying sufficient detail on core variables to fulfil the intended aim of the microdata products, the safeguarded sample is a valuable multi-purpose research file that will be used on a wide range of projects. (For Censuses prior to 2011, these data may have been referred to as 'Samples of Anonymised Records', or SARSs.)

This safeguarded sample is of 5% of the total population at Local Authority level (Northern Ireland), and contain a similar level of detail to the equivalent End User Licence Census 2001 Microdata samples. A similar Northern Ireland dataset at Regional level is held under SN 7769. These samples have a low risk of disclosure; but not nil. Registered UK Data Service Census users can download the data to their laptops after agreeing terms and conditions that include constraints on data management under remote storage conditions.

Further information can be found on the Northern Ireland Statistics and Research Agency (NISRA) Census microdata webpage.

Corresponding Regional and Local Authority level data for England and Wales are held under SNs 7605 and 7682, and for Scotland under SNs 7834 and 7835.

Accommodation designed or adapted for health conditions; Central heating; Household size; Nature of communal establishment; Number of cars and vans; Pensioner household; Student accommodation; Tenure; Type of accommodation; Type of Establishment; Type of landlord; Whether accommodation is self-contained; Ability in Irish; Ability in Ulster Scots; Age of individual; Alternative Household Composition; Approximated social grade; Comparison of where you live and work; Country of birth; Distance moved from address one year ago; Done voluntary work without pay in the last year; Economic Activity; Employment type; English proficiency; Ethnicity; Ever worked; Exact pension age (on Census Day) indicator; Family status; General health; Hours worked per week; Household language; Age of Households Reference Person (HRP); Country of birth of HRP; National Statistics Socio-Economic Classification (NS-SeC) of HRP; Social grade of HRP; Industry of business; Intention to stay in the UK; Last year worked; Level of highest qualifications; Lived outside Northern Ireland for more than one year; Living arrangements; Long-term health problem; Main language; Marital Status; National identity; NS-SeC; Number of individuals in household with long-standing illness/disability; Number of people in household who provide care; Number of persons per room; Number of visitors on census night; Occupation; Passports held; Person of pensionable age indicator; Position within communal establishment; Provision of unpaid care; Relationship to HRP; Religion; Schoolchild or student in full-time education; Sex; Travel to work; Unemployment history; Usual address one year ago; Whether concealed family; Workers in generation one of family; Workplace or place of study; Year of Arrival in Northern Ireland.

The aggregate data produced as outputs from censuses in the United Kingdom provide information on a wide range of demographic and socio-economic characteristics. They are predominantly a collection of aggregated, or summary counts of the numbers of people, families or households resident in specific geographical areas possessing particular characteristics drawn from the themes of population, people and places, families, ethnicity and religion, health, work, and housing.

Aggregate data for Census 2011 cover the full range of geographies employed within the census, from the smallest (output areas with an average of 150 persons in England and Wales) to the nation as a whole.

• Access data through InFuse
• Census aggregate data guide

Citation: Office for National Statistics. (2019). 2011 Census: Aggregate Data. [data collection]. UK Data Service. SN: 7427, http://doi.org/10.5257/census/aggregate-2011-2

The UK censuses took place on 27 March 2011. They were run by the Northern Ireland Statistics & Research Agency (NISRA), National Records of Scotland (NRS), and the Office for National Statistics (ONS) for both England and Wales. The UK comprises the countries of England, Wales, Scotland and Northern Ireland.

Statistics from the UK censuses help paint a picture of the nation and how we live. They provide a detailed snapshot of the population and its characteristics, and underpin funding allocation to provide public services. This is the home for all UK census data.

These statistics contain the first phase of main statistics results from Census 2021. This phase provides estimates for a number of census topics, including passports held, ethnic group, national identity, language, and religion.

Data are available for Northern Ireland and the 11 Local Government Districts.

IPUMS-International is an effort to inventory, preserve, harmonize, and disseminate census microdata from around the world. The project has collected the world's largest archive of publicly available census samples. The data are coded and documented consistently across countries and over time to facilitate comparative research. IPUMS-International makes these data available to qualified researchers free of charge through a web dissemination system. The IPUMS project is a collaboration of the Minnesota Population Center, National Statistical Offices, and international data archives. Major funding is provided by the U.S. National Science Foundation and the Demographic and Behavioral Sciences Branch of the National Institute of Child Health and Human Development. Additional support is provided by the University of Minnesota Office of the Vice President for Research, the Minnesota Population Center, and Sun Microsystems. Detailed metadata will be found in ipumsi_6.3_ie_1996_ddic.html within the Data Package. The related metadata describes the content of the extraction of the specified sample from the IPUMS International on-line extraction system.

Workplace Zone (WZ) centroids are point features that represent the 'master postcodes' for WZs. The centroid, or 'master postcode' was selected using an algorithm which calculates the postcode centroid within a WZ which has grid references closest to the worker-weighted centre of the DZ. These centroids / 'master postcodes' can be used to link WZs to other (higher level) geographies and produce a 'best-fit' match. They have been created by the National Records of Scotland (NRS), based on the WZ boundaries which were produced on behalf of NRS by the Office for National Statistics (ONS). WZs were a new output geography for Census 2011, initially produced using workplace data from the 2011 Census for England and Wales rather than the UK as a whole. They are designed to supplement the Output Area (OA) and Super Output Area (LSOA and MSOA) / Data Zone (DZ) geographies that were introduced with the 2001 Census, and have been constructed from OAs, or sub-divisions of these called postcode-level building-blocks. While OAs are designed to contain consistent numbers of persons based on where they live, WZs are designed to contain consistent numbers of workers, based on where people work. Following publication of WZs for England and Wales, coverage was subsequently extended to include Scotland and Northern Ireland using 2011 Census data to create a UK set of WZs produced by the ONS on behalf of NRS and the Northern Ireland Statistics and Research Agency (NISRA). WZs are designed to be a more suitable output geography for publishing workplace statistics.

These statistics contain the first phase of main statistics results from Census 2021. This phase provides estimates for a number of census topics, including passports held, ethnic group, national identity, language, and religion.

Data are available for Northern Ireland and the 11 Local Government Districts.

This dataset provides Census 2021 estimates for the number of households in Northern Ireland by accommodation type. The estimates are as at census day, 21 March 2021.

This spreadsheet contains 3 worksheets: a cover sheet; 1 sheet containing the data tables; and a notes sheet.

Data are available for Northern Ireland and the 11 Local Government Districts.

The census collected information on the usually resident population of Northern Ireland on census day (21 March 2021). Initial contact letters or questionnaire packs were delivered to every household and communal establishment, and residents were asked to complete online or return the questionnaire with information as correct on census day. Special arrangements were made to enumerate special groups such as students, members of the Travellers Community, HM Forces personnel etc. The Census Coverage Survey (an independent doorstep survey) followed between 12 May and 29 June 2021 and was used to adjust the census counts for under-enumeration.

Issues and corrections

DI002: Accommodation type

Census Office has noted differences in classification declared by a small number of respondents for accommodation type when compared to the accommodation type recorded by Land and Property Services (LPS) for the address. This can be explained by census respondents favouring selecting ‘semi-detached’ instead of ‘terraced (including end-terrace)’ for end-terrace properties.

Full details can be found on the NISRA website

This dataset provides Census 2021 estimates that classify usual residents in Northern Ireland by their national identity (national identity based). The estimates are as at census day, 21 March 2021. The national identity classification used is a 7-category classification corresponding to the tick box options on the census questionnaire. This dataset is not mutually exclusive; respondents are included under multiple groups, for example, if the respondent identifies as ‘British and Irish’ they are counted under both ‘British’ and ‘Irish’ groups.

The census collected information on the usually resident population of Northern Ireland on census day (21 March 2021). Initial contact letters or questionnaire packs were delivered to every household and communal establishment, and residents were asked to complete online or return the questionnaire with information as correct on census day. Special arrangements were made to enumerate special groups such as students, members of the Travellers Community, HM Forces personnel etc. The Census Coverage Survey (an independent doorstep survey) followed between 12 May and 29 June 2021 and was used to adjust the census counts for under-enumeration.

This dataset provides Census 2021 estimates that classify usual residents aged 3 and over in Northern Ireland by main language.

The census collected information on the usually resident population of Northern Ireland on census day (21 March 2021). Initial contact letters or questionnaire packs were delivered to every household and communal establishment, and residents were asked to complete online or return the questionnaire with information as correct on census day. Special arrangements were made to enumerate special groups such as students, members of the Travellers Community, HM Forces personnel etc. The Census Coverage Survey (an independent doorstep survey) followed between 12 May and 29 June 2021 and was used to adjust the census counts for under-enumeration.

This table reports the categories for which there are 10 or more usual residents. Where there are fewer than 10 usual residents for any category, these have been reported in a residual group which may or may not contain 10 or more usual residents in total.

Main language is reported as provided by respondents; those who stated 'Chinese' are recorded as 'Chinese (not otherwise specified)'. If a specific Chinese language has been stated, it is recorded separately.

Quality assurance report can be found here

This dataset provides census estimates for the number of usual residents in Northern Ireland for the census years 1851 - 2021 by broad age bands, and by sex.

The census collected information on the usually resident population of Northern Ireland on census day (21 March 2021). Initial contact letters or questionnaire packs were delivered to every household and communal establishment, and residents were asked to complete online or return the questionnaire with information as correct on census day. Special arrangements were made to enumerate special groups such as students, members of the Travellers Community, HM Forces personnel etc. The Census Coverage Survey (an independent doorstep survey) followed between 12 May and 29 June 2021 and was used to adjust the census counts for under-enumeration.

This dataset provides Census 2021 estimates that classify usual residents in Northern Ireland by single year of age, and by sex. The estimates are as at census day, 21 March 2021.

The census collected information on the usually resident population of Northern Ireland on census day (21 March 2021). Initial contact letters or questionnaire packs were delivered to every household and communal establishment, and residents were asked to complete online or return the questionnaire with information as correct on census day. Special arrangements were made to enumerate special groups such as students, members of the Travellers Community, HM Forces personnel etc. The Census Coverage Survey (an independent doorstep survey) followed between 12 May and 29 June 2021 and was used to adjust the census counts for under-enumeration.

This dataset provides Census 2021 estimates for the number of households in Northern Ireland by tenure. The estimates are as at census day, 21 March 2021.

The census collected information on the usually resident population of Northern Ireland on census day (21 March 2021). Initial contact letters or questionnaire packs were delivered to every household and communal establishment, and residents were asked to complete online or return the questionnaire with information as correct on census day. Special arrangements were made to enumerate special groups such as students, members of the Travellers Community, HM Forces personnel etc. The Census Coverage Survey (an independent doorstep survey) followed between 12 May and 29 June 2021 and was used to adjust the census counts for under-enumeration.

This spreadsheet contains 2 worksheets: a cover sheet and 1 sheet containing the data table.

Data are available for Northern Ireland and the 11 Local Government Districts.