Census definitions
These are the technical definitions used in relation to the census outputs.
Accommodation type
This refers to the type of accommodation used or available for use by a household. Examples include the whole of a terraced house, or a flat in a purpose-built block of flats.
Adaptation of accommodation
Household accommodation that has been adapted or designed for one or more of the following: internal wheelchair usage, external wheelchair access, other physical or mobility difficulties, visual difficulties, hearing difficulties, or other. This only refers to households - communal establishments were not asked this question.
Address one year ago
This refers to the place of usual residence for a person 12 months before 21 March 2021.
Adult
An adult in a household is defined as any person who is not a dependent child. This definition is used in most results from Census 2021. In results where a different definition is used it is clearly indicated.
Adult (alternative definition)
In a small number of census results, for example some versions of ‘Household composition’ or ‘Adult lifestage’, adult is used to refer to those aged 16 and over and children to those aged 15 and under. This definition is different from the standard definition for adults, children and dependent children used in most census results. When this definition is used, it is clearly indicated.
Adult lifestage
Adult lifestage classifies adults in households under the age of 54 by age, by the presence of dependent children in the household, and by the age of the youngest dependent child if any are present. Adults aged 55 and over are classified by age and whether they are in one or two-person households. Those aged 55 to 74 are further classified by the presence of dependent children.
Adult lifestage defines an adult as anyone aged 16 and over. This definition is different from the standard definition for adults, children and dependent children used in most census results.
Age
Age is derived from the date of birth question and is a person’s age at their last birthday on or prior to 21 March 2021. Dates of birth that imply an age over 115 are treated as invalid and the person’s age is imputed. Infants less than one year old are classified as 0 years of age.
Area
Census statistics use land area figures based on the Standard Area Measurements (SAM) method; the resultant land area measurements are defined by topographic boundaries (coastline and inland water) as at the end of 2021.
Area measurements are in hectares - the metric unit of area defined as 10,000 square metres or approximately 2.47 acres - there are 100 hectares in 1 km2.
Atheist
Those respondents who indicated they were Atheist are included in the no religion category for outputs.
Average household size
The average household size is equal to the total number of usual residents living in households in an area, divided by the total number of households with usual residents in that area.
Non usual residents staying at an address do not contribute to that household’s size because they are counted in the household of their place of usual residence.
Cars or vans
This applies to the number of cars or vans that are owned, or available for use, by members of a household. It includes company cars and vans that are available for private use. It does not include motorbikes or scooters.
The count of cars or vans in an area relates only to households. Cars or vans used by residents of communal establishments are not counted. Responses indicating a number of cars or vans greater than 20 were treated as invalid and a value was imputed.
Catholic
The Catholic category includes those respondents who gave their religion or religion brought up in as Roman Catholic, Catholic Apostolic Church, Ukrainian Catholic, Greek Catholic or Catholic.
Census day 2021
Census day 2021 was the day on which the population was asked to complete the Census 2021 questionnaire. This day was Sunday 21 March 2021. Respondents completing the questionnaire before or after this date were asked to provide answers which described their circumstances on 21 March 2021.
Central heating
Central heating is a central system that generates heat for multiple rooms. A household’s accommodation is classified as having central heating if it is present in some or all rooms (whether used or not). Central heating is classified by fuel type, for example, gas, electric (including storage heaters) or oil.
This information is not available for household spaces with no usual residents.
Central heating (household based) - (classification 1)
In classification 1 outputs, the central heating categories are mutually exclusive and will add up to 100%. This classification is based on households.
Central heating (system based) - (classification 2)
In classification 2 outputs, the central heating categories are not mutually exclusive and therefore may add up to more than 100%. This classification is based on central heating systems rather than households.
Child
There is no age limit applied to the definition of a child. For example, a married couple living with their son aged 40 would be classified as a family consisting of a married couple and their child unless the son has a spouse, civil partner, partner or child living in the household. This definition is used in most results from Census 2021. In results where a different definition is used, it is clearly indicated.
Child (alternative definition)
In a small number of census results, for example some versions of ‘Household composition’ or ‘Adult lifestage’, adult is used to refer to those aged 16 and over and children to those aged 15 and under. This definition is different from the standard definition for adults, children and dependent children used in most census results. When this definition is used it is clearly indicated.
Children with parents who live apart
Children shared between parents living apart are counted as usually resident at the address at which the child spends the majority of their time. If the child lives equally between parents then they are counted as usually resident at the address where they stayed overnight on 21 March 2021.
Civil partnership
‘In a civil partnership’ is one of the categories within the marital and civil partnership status variable. In the living arrangements classification a person not living in a couple can still be classified as in a civil partnership if they denote their marital or civil partnership status as in a civil partnership but have no civil partner resident in the household.
Cohabiting
Two people are described as cohabiting if they are living together as a couple but are not married to each other or in a registered civil partnership together.
A cohabiting person might be married or in a civil partnership (with someone not resident in the household) but will not be shown as married, in a civil partnership or separated in results relating to living arrangements, as cohabiting in this classification takes priority over legal marital or partnership status.
Cohabiting couple family
A cohabiting couple family consists of two people of any sex who are living together as a couple, with or without their children, but who are not resident with a married or a civil partner. Children included in the cohabiting couple family may belong to both members of the couple or only one. Children are included in the family only if they are not themselves living with a spouse, civil partner or partner, and do not have any children of their own in the household.
Cohabiting couples with their grandchildren are also considered a cohabiting couple family if there are no children from the intervening generation present in the household (note that children of the couple may also be present if they are not parents or grandparents of the youngest generation).
Cohabiting couple household
A cohabiting couple household is a household that comprises a cohabiting couple family and no other person. This definition is used in most results from Census 2021.
Communal establishment
A communal establishment is an establishment providing managed residential accommodation. Managed in this context means full-time or part-time supervision of the accommodation. The communal establishment resident figures also include people who were sleeping rough for Census 2021.
More information can be found in the population definitions on the NISRA website.
Communal establishment resident
A communal establishment resident is a person whose place of usual residence is in managed residential accommodation. This means any person who was living, or expected to live in a communal establishment for six months or more. Individuals resident in a communal establishment for less than six months are included as resident at their home address.
More information can be found in the population definitions on the NISRA website.
Country of birth
Country of birth is the country in which a person was born.
Daytime population
The daytime population of an area is defined as “All usual residents who are either in employment or full-time students in the area, or not in employment or full-time students but are usually resident in the area”. People who work or study mainly at or from home, or do not have a fixed place of work or study, are included in the area of their usual residence.
The following population groups are excluded from the daytime population of an area:
- those living in Northern Ireland but working or studying in England, Wales, Scotland, or outside the UK; and
- those with a place of work or study in Northern Ireland but who are not usually resident in Northern Ireland.
Dependent child
A dependent child is a person aged 0 to 15 in a household (whether or not in a family) or aged 16 to 18 in full-time education and living in a family with his or her parent(s) or grandparent(s). It does not include any children who have a spouse, partner or child living in the household.
Distance travelled to place of work or study
For usual residents who work or study in Northern Ireland, their distance travelled to place of work or study is calculated as the straight line distance, in kilometres, between their place of residence and their place of work or study.
For usual residents who work or study outside of Northern Ireland, this variable indicates whether they work or study in: England, Scotland or Wales; in Republic of Ireland; or outside the United Kingdom and Ireland.
Economic activity
Economic activity relates to whether or not a person who was aged 16 and over was working or looking for work in the week before census. Rather than a simple indicator of whether or not someone was in employment at the time, it provides a measure of whether or not a person was an active participant in the labour market.
A person’s economic activity is derived from their ‘activity last week’. This is an indicator of their status or availability for employment - whether employed, actively looking for work, waiting to start a new job, available to start a new job, or their status if not employed or not seeking employment. Additional information included in the economic activity classification is also derived from information about the number of hours a person works and their type of employment - whether employed or self-employed.
Economically active
A person aged 16 and over is described as economically active if, in the week before the census, they were:
- in employment, as an employee or self-employed;
- not in employment, but were seeking work and ready to start work within two weeks; or
- not in employment, but waiting to start a job already obtained and available.
Full-time students who fulfil any of these criteria are classified as economically active and are counted separately in the ‘full-time student’ category of economically active - they are not included in any of the other categories such as employees or unemployed.
Economically inactive
A person aged 16 and over is described as economically inactive if, in the week before the census, they were not in employment but did not meet the criteria to be classified as ‘unemployed’. This includes a person looking for work but not available to start work within two weeks, and anyone not looking for work, or unable to work.
Students who fulfil any of these criteria are also classified as economically inactive. This does not necessarily mean they were in full-time education and excludes students who were working or in some other way economically active.
Employed
A person aged 16 and over is defined as employed (or in employment) if in the week before the census they carried out at least one hour’s paid work, either as an employee or self-employed.
This includes casual or temporary work, being away from work ill, on maternity or paternity leave, on holiday or temporarily laid off.
Employee
An employee is a person aged 16 and over in employment doing paid work for an individual or organisation.
This relates to a person’s main job or, if not working at the time of the census, their last main job.
Ethnic group
Person’s ethnic group as declared in the census.
European Union (EU)
European Union is as defined on census day (21 March 2021). The 27 EU member states were Austria, Belgium, Bulgaria, Croatia, Republic of Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, and Sweden.
Family
A family is defined as a group of people who are either:
- a married, civil partnership, or cohabiting couple, with or without children;
- a lone parent with children;
- a married, civil partnership, or cohabiting couple with grandchildren but with no children present from the intervening generation; or
- a single or couple grandparent with grandchildren but no children present from the intervening generation.
Children in couple families need not belong to both members of the couple.
For single or couple grandparents with grandchildren present, the children of the grandparent(s) may also be present if they are not parents or grandparents of the youngest generation present.
Family Reference Person (FRP)
The Family Reference Person (FRP) is identified by criteria based on the family make up.
In a lone parent family it is taken to be the lone parent.
In a couple family, the FRP is chosen from the two people in the couple on the basis of their economic activity (in the priority order; full-time job, part-time job, unemployed, retired, other). If both people have the same economic activity, the FRP is identified as the elder of the two or, if they are the same age, the first member of the couple on the form.
Where there is only one family in the household, the FRP becomes the Household Reference Person (HRP).
Frequency of speaking Irish
Frequency of speaking Irish is how often people speak Irish. The frequency can be: daily; weekly; less often; or never.
Frequency of speaking Irish is only applicable to people who can speak Irish.
Frequency of speaking Ulster-Scots
Frequency of speaking Ulster-Scots is how often people speak Ulster-Scots. The frequency can be: daily; weekly; less often; or never.
Frequency of speaking Ulster-Scots is only applicable to people who can speak Ulster-Scots.
Full-time student
A full-time student is a person of any age who has indicated that they are a schoolchild or student in full-time education.
Full-time students and schoolchildren who are economically active are identified separately in the economic activity tables. They are not included in the other categories of economically active such as ‘employees’ or ‘unemployed’.
In tables on occupation and industry, where students are not identified separately, they are included under the appropriate occupation or industry.
In the National Statistics Socio-economic Classification all full-time students are recorded in the ‘full-time students’ category regardless of whether they are economically active or not (no outputs published yet).
The economic activity questions are only asked of people aged 16 and over.
Schoolchildren and students in full-time education studying away from their family home are treated as usually resident at their term-time address.
Full-time working
See Hours worked
General health
General health is a self-assessment of a person’s general state of health. People were asked to assess whether their health was very good, good, fair, bad or very bad. This assessment is not based on a person’s health over any specified period of time.
Highest level of qualification
The highest level of qualification is derived from the question asking people aged 16 years and over to indicate all types of qualifications held. For qualifications gained outside Northern Ireland, respondents were directed to select the nearest equivalent.
The response options covered a range of academic, professional, and vocational qualifications (including apprenticeships).
These are combined into four categories for the highest level of qualification, plus categories for apprenticeships, other qualifications (which includes qualifications where equivalents were not known), and one for no qualifications:
- No qualifications;
- Level 1: 1 to 4 GCSEs, O levels, CSEs (any grades); 1 AS Level; NVQ level 1; or equivalent;
- Level 2: 5 or more GCSEs (A*-C or 9-4), O levels (passes), CSEs (grade 1); 1 A level, 2-3 AS Levels; NVQ level 2, BTEC General, City and Guilds Craft; or equivalent;
- Apprenticeship;
- Level 3: 2 or more A Levels, 4 or more AS Levels; NVQ Level 3, BTEC National, OND, ONC, City and Guilds Advanced Craft; or equivalent;
- Level 4 and above: Degree (BA, BSc), foundation degree, NVQ Level 4 and above, HND, HNC, professional qualifications (teaching or nursing, for example), or equivalent; and
- Other: Other qualifications, equivalent unknown.
Hours worked
The number of hours that a person, aged 16 and over in employment in the week before the census, worked in their main job. This includes paid and unpaid overtime.
Full-time working is defined as working 31 hours or more per week
Part-time working is defined as working 30 hours or less a week.
Household
A household is either:
- one person living alone; or
- a group of people (not necessarily related) living at the same address who share cooking facilities and share a living room, sitting room or dining area.
Householder
The householder is a person who usually lives at an address, and who on their own or with someone else:
- owns or rents the accommodation; or
- pays the household bills and expenses.
Household composition
Household composition classifies households according to the relationships between the household members. Households consisting of one family and no other usual residents are classified according to the type of family (married, civil partnership or cohabiting couple family, or lone parent family) and the number of dependent children. Other households are classified by the number of people, the number of dependent children, or whether the household consists only of students or only of people aged 65 and over.
Household deprivation
The dimensions of deprivation used to classify households are indicators based on four selected household characteristics:
- education - a household is classified as deprived in the education dimension if no one has at least level 2 education and no one aged 16 to 18 years is a full-time student;
- employment - a household is classified as deprived in the employment dimension if any member, not a full-time student, is either unemployed or economically inactive due to long-term sickness or disability;
- health - a household is classified as deprived in the health dimension if any person in the household has a health problem or disability lasting or expected to last 12 months or more that reduces their ability to carry out day to day activities and/or who has general health that is bad or very bad; and
- housing - a household is classified as deprived in the housing dimension if the household’s accommodation is either overcrowded or has no central heating.
Household language
Household language classifies households by the combination of persons aged 16 and over, and those aged 3-15 years, within a household that have English as a main language.
Household lifestage
Household lifestage classifies households according to the age of the Household Reference Person (HRP), whether they are in a one or two or more person household, and for households with two or more people, the presence of dependent children in the household.
Household Reference Person (HRP)
The concept of a Household Reference Person (HRP) was introduced in the 2001 Census (in common with other government surveys in 2001/2) to replace the traditional concept of the ‘head of the household’. HRPs provide an individual person within a household to act as a reference point for producing further derived statistics and for characterising a whole household according to characteristics of the chosen reference person.
For a person living alone, it follows that this person is the HRP.
If a household contains only one family (with or without ungrouped individuals) then the HRP is the same as the Family Reference Person (FRP).
No FRP can be identified for families in which there is generational divide between family members that cannot be determined (other related family). Members of these families are treated the same as ungrouped individuals.
If there is more than one family in a household the HRP is chosen from among the FRPs using the same criteria used to choose the FRP. This means the HRP will be selected from the FRPs on the basis of their economic activity, in the priority order:
- Economically active, employed, full-time, non-student
- Economically active, employed, full-time, student
- Economically active, employed, part-time, non-student
- Economically active, employed, part-time, student
- Economically active, unemployed, non-student
- Economically active, unemployed, student
- Economically inactive, retired
- Economically inactive, other
If some or all FRPs have the same economic activity, the HRP is the eldest of the FRPs. If some or all are the same age, the HRP is the first of the FRPs from the order in which they were listed on the questionnaire.
If a household is made up entirely of any combination of ungrouped individuals and other related families, the HRP is chosen from among all people in the household, using the same criteria used to choose between FRPs. Students at their non term-time address cannot be the HRP.
Household resident
A household resident is a person whose place of usual residence is in an individual household, and not within managed residential accommodation in a communal establishment.
Household size
A household’s size is the number of people resident in the household who are usual residents of the UK. People are included at their usual place of residence in the UK, so non usual residents listed on the form at an address do not contribute to the household size.
Household space
A household space is the accommodation used or available for use by an individual household. Household spaces are identified separately in census results as those with at least one usual resident (occupied), and those that do not have any usual residents (unoccupied).
A household space with no usual residents may still be used by visitors who were present on census night.
Vacant household spaces and household spaces that are used as second addresses are also classified in census results as household spaces with no usual residents.
Industry
The classification of people aged 16 and over by the industry they work in (or worked in). This relates to their main job and is determined by the response to the question asking for a description of the main activity of the business of the person’s employer (or own business if self-employed). The responses are coded to a modified version of the UK Standard Industrial Classification of Economic Activities 2007 - UK SIC (2007).
Knowledge of Irish
A person has knowledge of Irish if they can do one or more of the following:
- understand Irish;
- speak Irish;
- read Irish; or
- write Irish.
Knowledge of Ulster-Scots
A person has knowledge of Ulster-Scots if they can do one or more of the following:
- understand Ulster-Scots;
- speak Ulster-Scots;
- read Ulster-Scots; or
- write Ulster-Scots.
Living arrangements
The living arrangements classification combines responses to the question on marital and civil partnership status with information about whether or not a person is living in a couple. This topic is only applicable to people in households.
Living arrangements differs from marital and civil partnership status because cohabiting takes priority over other categories. For example, if a person is divorced and cohabiting, then in results for living arrangements they are classified as cohabiting.
Living in a couple
The term ‘living in a couple’ includes people who are living together in a couple and are either married, in a civil partnership, or are cohabiting with a partner.
Local Government District (LGD)
Northern Ireland is divided into 11 local government districts (LGDs), these are also known as local councils. Each LGD is subdivided into electoral wards.
| Geography | Geography Code |
|---|---|
| Antrim and Newtownabbey | N09000001 |
| Armagh City, Banbridge and Craigavon | N09000002 |
| Belfast | N09000003 |
| Causeway Coast and Glens | N09000004 |
| Derry City and Strabane | N09000005 |
| Fermanagh and Omagh | N09000006 |
| Lisburn and Castlereagh | N09000007 |
| Mid and East Antrim | N09000008 |
| Mid Ulster | N09000009 |
| Newry, Mourne and Down | N09000010 |
| Ards and North Down | N09000011 |
Lone parent family
A lone parent family consists of a father or mother with his or her children where the parent does not have a spouse, civil partner or partner in the household, and the children do not have a spouse, civil partner or child in the household. A lone grandparent with his or her grandchildren are also considered a lone parent family if there are no children in the intervening generation present in the household (note that children of the grandparent may also be present if they are not parents or grandparents of the youngest generation).
Lone parent household
The term ‘lone parent household’ is used to describe a household that comprises a lone parent family and no other person.
Long-term health condition
A long-term health condition is one which has lasted, or is expected to last, at least 12 months. You could have multiple responses to this question. In census, this is a self-assessment question.
Long-term health problem or disability
A long-term health problem or disability is that which limits daily activities and which has lasted, or is expected to last, at least 12 months. This includes problems that are due to old age. In census, this is a self-assessment question.
Long-term unemployed
See Unemployed
Main job
The main job is the job in which a person usually works the most hours. For people not working at the time of the census the main job relates to the person’s last job. Topics based on employment all relate to a person’s main job.
Main language
Person’s main language as declared in the census.
Marital and civil partnership status
This classifies a person according to their legal marital or civil partnership status on census day 21 March 2021.
It is the same as the 2011 Census variable ‘Marital Status’ but has been updated for Census 2021 to reflect the Marriage and Civil Partnership Regulations that came in to force in 2020.
Marital and civil partnership states include:
- single (never married or never registered a civil partnership);
- married;
- in a civil partnership;
- separated (but still legally married or still legally in a civil partnership);
- divorced or formerly in a civil partnership which is now legally dissolved; or
- widowed or surviving partner from a civil partnership.
Although the term ‘single’ is widely used to cover people in a number of states such as divorced or separated, in census results the term ‘single’ is used to refer only to someone who has never been married or in a registered civil partnership.
Married
Married is one of the categories within the marital and civil partnership status variable. In the living arrangements classification a person not living in a couple can be classified as married if they denote their marital status as married but have no spouse or partner resident in the household.
Married couple family
A married couple family consists of two people married to each other with or without children. The children may belong to both members of the couple or only one. Children are included in the family only if they are not themselves living with a spouse, civil partner or partner and do not have any children of their own in the household.
A married couple with their grandchildren are also considered a married couple family if there are no children in the intervening generation present in the household (note that children of the couple may also be present if they are not parents or grandparents of the youngest generation).
Median age
The median age is the middle value when all the ages are arranged in order from youngest to oldest, where age is age at their last birthday, on or prior to 21 March 2021 (in whole years).
Method of travel to work or study
The method of travel used for the longest part, by distance, of the usual journey to work or place of study (including school).
Multiple ethnic groups
Multiple ethnic groups classifies households by the diversity in ethnic group of household members in different relationships - for example, different ethnic groups between generations only, or different ethnic groups within partnerships only.
National identity
The nationality or nationalities that the person identifies with. It is not dependent on ethnic group or citizenship.
People were asked to tick all options that they felt applied to them. This means that in results relating to national identity, people may be classified with a single national identity or a combination of identities.
British identity excludes responses indicating an identity related to the British Virgin Islands and British Overseas Territories.
National identity (person based) – classification 1
In classification 1 outputs, the national identity categories are mutually exclusive and will add up to 100%. This classification is based on persons.
National identity (national identity based) – classification 2
In classification 2 outputs, the national identity categories are not mutually exclusive and therefore may add up to more than 100%. This classification is based on national identities rather than persons.
National Statistics Socio-economic Classification (NS-SeC)
The National Statistics Socio-economic Classification (NS-SeC) provides an indication of socio-economic position based on occupation. It is an Office for National Statistics (ONS) standard classification. To assign a person to an NS-SeC category their occupation title is combined with information about their employment status, whether they are employed or self-employed, and whether or not they supervise other employees. Full-time students are recorded in the’ full-time students’ category regardless of whether they are economically active or not. The rebased version of NS-SEC used in census results uses occupation coded to Standard Occupational Classification (SOC2020 volume 3).
In Census 2021 results, because the census did not ask a question about the number of employees at a person’s workplace, the reduced method of deriving NS-SEC (which does not require this information) is used. Note that the categories L16 (Occupations not stated or inadequately described) and L17 (Not classifiable for other reasons) are not included in census tables because missing answers are imputed.
Not living in a couple
A person ‘not living in a couple’ is someone not in a co-residential relationship (marriage, civil partnership, cohabiting). A person ‘not living in a couple’ can include those married or in a civil partnership but have no spouse or partner resident in the household.
Number of rooms
Number of rooms is the habitable rooms available in a household’s accommodation, modelled using information from the Land & Property Services Domestic Property List and other sources. The count includes rooms such as living rooms, studies, bedrooms, and separate dining rooms. It does not include bathrooms, toilets, halls or landings, conservatories, utility rooms and kitchens used solely for kitchen purposes (i.e. those without dining/sitting areas).
Census 2021 did not ask a ‘number of rooms’ question. There are definitional differences between Census 2011 and the modelled count produced for Census 2021. Therefore, comparisons cannot be made between Census 2021 and Census 2011.
Occupancy rating
Occupancy rating provides a measure of whether a household’s accommodation is overcrowded, ideally occupied or under occupied. The ages of the household members and their relationships to each other are used to derive the number of rooms they require, based on a standard formula. The number of rooms required is subtracted from the number of rooms in the household’s accommodation to obtain the occupancy rating. An occupancy rating of -1 implies that a household has one fewer room than required, 0 suggests that a household’s accommodation has an ideal number of rooms, and +1 implies that they have one more room than the standard requirement.
The number of rooms data are modelled using information from the Land & Property Services Domestic Property List and other sources. Census 2021 did not ask a ‘Number of rooms’ question. There are definitional differences between Census 2011 and the modelled count produced for Census 2021. Therefore, comparisons cannot be made between Census 2021 and Census 2011.
Occupation
The classification of people aged 16 and over by the occupation they work in (or worked in). A person’s occupation is coded from the response to the question asking for the full title of the main job and the description of what is done in that job, including any supervisory or management responsibilities. It is coded to the 2020 edition of the Standard Occupational Classification (SOC2020).
Owner occupied
This includes accommodation that is either owned outright, owned with a mortgage or loan, or shared ownership (part rents and part owns).
Part-time working
See Hours worked
Passports held
Results for passports held classify a person according to the passport or passports that they held at the time of Census 2021. People were asked to indicate all that applied to them. This means that in results relating to passports held, people may be classified with a single passport or a combination of passports.
The categories EU countries and non-EU countries relate to the European Union (EU) as at March 2021.
Passports held (person based) – classification 1
In classification 1 outputs, the passports held categories are mutually exclusive and will add up to 100%. This classification is based on persons.
Passports held (passports based) – classification 2
In classification 2 outputs, the passports held categories are not mutually exclusive and therefore may add up to more than 100%. Those who hold a United Kingdom or Irish passport, and any other type of passport, will appear in each applicable category. This classification is based on passports held rather than persons.
Permanently sick/disabled
This is a sub-category of ‘economically inactive’. There is no direct connection with limiting long-term illness.
Persons per room
The number of persons per room is equal to the number of usual residents in a household divided by the number of rooms in that household’s accommodation.
The number of rooms data are modelled using information from the Land & Property Services Domestic Property List and other sources. Census 2021 did not ask a ‘Number of rooms’ question. There are definitional differences between Census 2011 and the modelled count produced for Census 2021. Therefore, comparisons cannot be made between Census 2021 and Census 2011.
Place of work or study
The place a person travels to for their main job or course of study (including school).
Population density
Population density is the number of usual residents standardised by the size of the area considered. It is worked out by dividing the number of residents in an area by the size of the area. For Census 2021 the measure of area size is hectares. A hectare is the metric unit of area defined as 10,000 square metres or approximately 2.47 acres.
Private rented
This includes accommodation that is rented from a private landlord or letting agency, employer of a household member, relative or friend of a household member, or other non-social rented.
Proficiency in English
Proficiency in English classifies people, whose main language is not English, according to their ability to speak English. A person is classified in one of the following categories:
- can speak English very well;
- can speak English well;
- cannot speak English well; or
- cannot speak English.
Provision of unpaid care
A person is a provider of unpaid care if they give any help or support to anyone because of long-term physical or mental health conditions or illnesses, or problems related to old age. This does not include any activities as part of paid employment.
Note that there is no specific reference to whether this care is provided within the household or outside the household. Therefore, no explicit link can be created to infer that an individual providing care is providing it to a person within the household who has poor general health, or a long-term health problem or disability.
Religion
Those people who regard themselves as belonging to a religion are asked to indicate which religion, religious denomination or body they belong to. Missing answers for religion are not imputed, so the output classifications include a not stated category. Those people who do not regard themselves as belonging to any religion are classified as no religion.
This is also referred to as current religion.
Religion or religion brought up in
This variable combines the responses to the questions on religion and religion brought up in. It identifies the religious group that someone belongs to, or the religious group brought up in for people who do not belong to any religion.
Responses have been categorised as Catholic, Protestant, Other Christian and Christian Related, or Other Religions on the basis of the best available information, although it is acknowledged that the categorisation of some of the smaller religions is open to interpretation. Further information is provided in Census 2021 guidance note on religion questions and religion outputs.
This is also referred to as religion of upbringing.
Renewable energy systems
Renewable energy systems are used to generate heat or energy for a household. Information on renewable energy systems was collected for the first time in Census 2021.
A household can have one or more renewable energy systems, examples of those present are; solar panels for electricity, solar panels for heating water, biomass and wind turbines.
Residence type
This defines the type of residence that a person lives in. It categorises people as living in a household or living in a communal establishment.
Response rate (household)
Statistical methods are adopted to ensure that census results represent 100 per cent of the population. A measure of census quality is the household response rate – in total, 97 per cent of household returns came directly from householders.
Same-sex couples
Same-sex couples are two people of the same sex who live together as a couple. This includes people who are currently or formerly in a registered same-sex civil partnership, same-sex marriage and those living in a cohabiting same-sex couple.
Couples of the same sex who are not in a registered same-sex civil partnership are generally included in census results in categories relating to cohabiting couple families.
Self-employed
Self-employed people own and operate their own business, professional practice or similar enterprise, including those operated with a partner. This relates to a person’s main job or, if not working at the time of the census, their last main job.
This can include people who work freelance, which means someone who is self-employed and works (or worked) for different companies on particular pieces of work.
Self-employed people who are not freelance can have employees who work for them.
Sex
Classification of a person to either male or female.
Sexual orientation
A person’s sexual orientation as stated in the census. This question was only asked of people aged 16 years and over. Missing answers for sexual orientation were not imputed, so the output classification includes a not stated category.
Short-term unemployed
See Unemployed
Single family household
A household is classified as a single family household if there is only one family in the household and there are no non-family people (ungrouped individuals).
Tenure
Tenure provides information on whether a household owns or rents the accommodation that it occupies. It is derived from the response to the question asking whether the household owns or rents its accommodation and, if rented, further derived from the response to the question asking who the landlord is.
Term-time address
A term-time address is the address where a schoolchild or student in full-time education and studying away from their family home is resident for the part of the year when classes are held in schools, colleges and universities.
Schoolchildren and students in full-time education with a term-time address that was different to their family home were counted as usually resident at their term-time address.
Unemployed
A person is classified as unemployed if they are without a job, have actively sought work in the last four weeks and are available to start work in the next two weeks; or are out of work, have found a job and are waiting to start it.
Short-term unemployed – A person is defined as being short-term unemployed if they reported that they have previously worked within the last 12 months.
Long-term unemployed – A person is defined as being long-term unemployed if they reported that they have previously worked, but have not worked in the last 12 months.
Usual resident of the UK
A usual resident of the UK is anyone who, on 21 March 2021:
- is in the UK and is staying in the UK for a period of 3 months or more; or
- has a permanent UK address and is outside the UK and is staying outside the UK for less than 12 months.
Workplace population
The workplace population of an area is defined as “All usual residents aged 16 and over who are in employment and whose workplace is in the area”. People who work mainly at or from home or do not have a fixed place of work are included in the area of their usual residence.
The following population groups are excluded from the workplace population of an area:
- those not working the week before 21 March 2021;
- those living in Northern Ireland but working in England, Wales, Scotland, or outside the UK; and
- those with a place of work in Northern Ireland but who are not usually resident in Northern Ireland.
Year of arrival to live in Northern Ireland
The year that people arrived to live in Northern Ireland. This question was only asked of people who were born outside Northern Ireland.
Social rented
This includes accommodation that is rented from the Northern Ireland Housing Executive, a housing association or a charitable trust.