Explanatory notes

The population count in the Census 2021 results includes all usually resident inhabitants of the Czech Republic.

The place of usual residence is defined as the place where a person predominantly resides, spends his/her daily rest time, regardless of temporary absence due to recreation, visits, business trips, stay in a health facility, etc., and where he/she is a member of a particular household.

For the inclusion of a person in the usual resident population of the Czech Republic, the criterion of length of stay of at least 12 months or the intention of long-term residence is decisive.

The declaration on the Census questionnaire concerning the person's actual residence (regardless of the place of permanent residence or permitted temporary residence) was decisive for deriving the person's usual place of residence; other information on actual residence one year prior to the census, data on the place of permanent residence or permitted temporary residence and the place of enumeration were also evaluated.

Persons in institutions are persons with usual residences in all types of collective living quarters (such as elderly care homes, children’s homes, lodging houses, prisons etc.).

Persons in other housing units are persons with usual residences in improvised housing units, mobile housing units, recreational cottages or chalets or in buildings intended for habitation but not in conventional dwellings (in units not intended for habitation such as garages or offices).

Homeless are persons who declared “No housing (homeless)” as their housing arrangements on a census questionnaire. According to international recommendations, the place of enumeration is taken as the place of usual residence of a homeless person.

Data on citizenship are taken from the population register. Foreigners are inhabitants with a foreign citizenship without citizenship of the Czech Republic.Persons with two or more citizenships are allocated to only one country of citizenship in the following order: Czech Republic, other EU Member State, other European country, other country outside Europe.  

The ethnicity was filled in by each person according to their own decision. It was possible to indicate up to two ethnicities or to indicate none (this was optional).

As the mother tongue was stated the language spoken with the enumerated person as a child by his/her mother or those who raised him/her (the first language the enumerated person learned to speak). It was possible to state two languages.

The completion of the information on religious beliefs was voluntary for the respondents and they could declare in their answer whether they were believers and state the religious trend, movement, church or society to which they belonged or whether they were without religious belief.

Marital status is the de jure status, i.e. the legal marital status of a person. In addition to persons with unidentified marital status, the difference between the sum for each marital status category and the total represents persons with registered partnerships.

Registered partnership ascertains the de jure status, or legal status - of a registered partnership of persons of the same sex entered into according to Act No. 115/2006 Coll., on Registered Partnerships, or pursuant to the valid legal regulations abroad.

The number of children born alive was collected only for women aged 15 and over during the Census. It includes all children born alive until the decisive moment (during marriage as well as outside of marriage). The number also includes the cases when any of the children died later on.

The highest educational attainment was collected only for persons aged 15 and over according to the highest school completed. The data provided on the Census questionnaire were supplemented with information on education from administrative sources. Persons who received their education in a private or foreign educational institution without accreditation by the Ministry of Education reported the corresponding level of education in the Czech education system.

The place of residence at birth is defined as the place of usual residence at birth of the enumerated person, i.e. where the enumerated person lived directly right after birth.

The place and type of registered residence were for 2021 Census taken from information systems of Ministry of Interior. It concerns Czech citizens and also foreigners with a registered residence in Czechia. The place of registered residence is not always identical to the place of usual residence surveyed in the Census.

Labour force (currently active population) represents employed persons (working) and unemployed.

Employed are all persons aged 15 or over who at Census reference date had a formal attachment to their job or were engaged in any activity for pay or profit for at least one hour per week. Labour force includes also working pensioners, working students and persons on maternity leave (28 or 37 weeks).

Persons with the formal attachment to their job are employees and self-employed with a business licence regardless of hours worked, a type of job (permanent, temporary) or a type of an employment relationship, contract or agreement.

Unemployed are all persons aged 15 or over who at Census reference date were not in employment and seeking employment (through the Employment office or by other means).

Persons outside the labour force (not economically active) are persons, who are neither employed nor unemployed. It includes not working pensioners, other non-working with their own source of livelihood, persons on parental leave, not working students, homemakers, preschool children and other dependent persons.

Persons with own income include all employed persons as well as (among persons outside the labour force) non-working pensioners and others with their own source of livelihood.

Employed persons are classified by status in employment, occupation and industry according to the main job at the Census reference date.

Status in employment was collected only from administrative data sources (IS ČSSZ, GFŘ data, RES).

Employers are self-employed with employees. Own-account workers are self-employed without employees. Employees have paid employment jobs.

Occupation (profession performed) refers to the type of work done as defined by the main tasks and duties performed in the job.

Industry (branch of economic activity) refers to the kind of production or economic activity of the employer or the scope of business.

Note: All percentage indicators refer only to persons with the identified characteristics.

The question on place of work/school was completed only by employed (working) persons and students. Students who were also working filled in a location of place of work. The place of work was entered as the address of the current workplace (not the headquarters, for example).

Persons who had no fixed location of work but started their work always at the same place (for example workers in transportation – drivers etc.) stated the place where they started their workday. Persons who often changed their location of work, stated an employment with “no fixed place of work”.

A question on frequency of commuting to work or school was completed by all employed persons and students, excluding persons who stated they worked/studied at their place of usual residence and persons with no fixed place of work. Persons who commuted from a different place than their place of usual residence were included in a category „from a different place than usual residence“.

A question on the mode of transport used for commuting to work or school completed all employed persons and students, excluding persons working/studying at their place of usual residence. It was possible to fill in one main mode of transport, i.e. for the longest part of the way, and further two at most for the rest of the way.

Persons commuting to work or school are employed (working) or students, whose place of work or place of school was at different place than their place of usual residence. Persons working/studying at their place of usual residence, persons with no fixed place of work and person with not identified place of work/school are not included in commuting to work/school.

Households are composed of persons with a common place of usual residence living in a same dwelling or other type of housing. The data on households were compiled from records of relationship on a Census questionnaire which were supplemented with data from administrative sources of Ministry of Interior.

A dwelling household consists of persons living together in one dwelling.

Housekeeping household consists of persons who run the household together, i.e. they share household expenses such as food, housing costs etc. A housekeeping household includes also children, who live there even if they do not contribute to the household expenditures. Types of housekeeping households:

• Household formed by one-couple family – includes husband-wife couples, cohabiting opposite-sex couples – i.e. consensual union, registered partnership, or cohabiting same-sex couples, always with or without resident children
• Household formed by lone-parent family – one parent with at least one resident child
• Household formed by two or more families
• Non-family multi-person household – two or more related or non-related persons who run the household together and do not form a family household; this includes also a grandparent-grandchild household (excluded grandparent couples who form a one-couple family)
• One-person household

The household formed by one-couple family may include other persons if they share the household.

Married couples/registered unions include married husband-wife couples and registered partnerships, i.e. de jure unions.

Cohabitating couples include couples in consensual union (de facto marriages and de facto partnerships). These are persons living in informal partnerships who have declared this cohabitation on the Census form, regardless of their actual marital status.

Consensual union opposite-sex couple is an informal partnership between a man and a woman as husband and wife, i.e. a de facto union without de jure marriage.

Consensual union same-sex couple is an informal same-sex partnership, i.e. a de facto partnership without a registered partnership.

In the Census results, one-family households are classified by, among other things, the number of dependent children. A dependent child is any person in one-family household whose status in the household is “a child“, is not included in the labour force and is also 0-25 years of age.

The figure for zero dependent children (no dependent children) includes both one-couple families that are completely childless and also one-couple and lone-parent families with children (i.e. with persons with the household status "child") but who do not qualify as dependent children because they are over 25 years of age or are in the labour force.

Dependent persons (or dependent household members) include dependent children and other dependants. Other dependants are persons in a one-family household who are not included in the labour force, have the household status of “child” or “other person in the household”, but do not meet the conditions for classification as dependent children.

The housekeeping household were processed for persons living in dwellings, in other housing units and also for families or non-family multi-person households in institutions. Single persons living in institutions and homeless persons are not included in the number of housekeeping households.

The abbreviation HD in the text of the tables stands for a housekeeping household.

The type of housing arrangements / type of housing for all persons and households was ascertained in the Census. In addition to conventional dwelling, a distinction is made for persons in housing arrangements in collective living quarters and also in various types of housing outside the dwelling stock in other buildings and other housing units (cottages, shelters, mobile housing) and homeless persons.

Other characteristics were collected only for occupied dwellings.

A dwelling is structurally separate and independent premise consisting of a room or suite of rooms which meet the requirements and are intended for habitation.

An occupied dwelling is a unit in which at least one person has his or her usual place of residence.

An unoccupied dwelling is a unit that is not the usual place of residence of any person.

Tenure status refers to the status of the occupant of the dwelling that is a household which lives there.

A dwelling in own house is a dwelling where an occupant is also owner or co-owner of the house.

An occupant of a dwelling in private ownership is listed in the land registry as the owner of the unit.

Other free use of dwelling is usually based on family connections or an agreement of an occupant and an owner of the dwelling or a building. The occupant does not have a rental contract but may cover living expenses (electricity, gas, water, sewage disposal) independently.

A rented dwelling is occupied on the basis of a rental agreement; this also includes cases of persons living in a sublet in a rented dwelling.

A dwelling in cooperative ownership is a unit owned by a housing cooperative and the occupant of the unit is also a member of that cooperative.

Other tenure status covers all cases of tenure status not listed above (i.e. previously service flats or caretaker’s flats).

A room is defined as a space in a dwelling (a living room, bedroom, dining room, kitchen) designed for habitation with a floor space of at least 4 square metres.

Total floor space is an area measured along the inside of the unit’s circumferential wall, stated in square meters and rounded to a whole number. The total floor space includes area of all rooms and other spaces in the dwelling (amenities, front hall, etc.). It does not include other spaces belonging to a dwelling such as inhabitable cellars or attics, balconies, or enclosed balconies (even if enclosed by glass).

Central remote heating is a heating installation outside the building, usually for more houses.

Central house heating is a heating installation in the building, usually used for heating in 2 or more dwellings in the house.

Central dwelling heating is a heating installation only for one dwelling; it is connected to a single heat source (heater) and is operated directly by an occupant of the dwelling. This type of heating covers heating in family houses with one dwelling, regardless of a location of the heater (heater in a room in the dwelling or e.g. in a basement).

Local heater/stove means heating by heat sources located in individual rooms of the dwelling. It covers all types of heaters or heat sources regardless of a fuel type (e.g. including accumulator stoves, WAW, space heaters and fireplaces).

Position of dwelling in the house means a floor where the main entrance to the dwelling is located. In case of an attic dwelling, the attic is considered to be another proper floor.

Note: All percentage indicators refer only to dwellings with the identified characteristics.

The number of houses includes all houses intended for living purposes, i.e. buildings with dwellings (apartments) and buildings containing other premises intended for living or longer-term accommodation, such as accommodation facilities. The number of houses thus includes, in addition to family houses and apartment buildings, also service buildings with a dwelling unit (e.g. a school with a dwelling), various establishments intended for housing - e.g. youth hostels, boarding houses, children's homes, social welfare institutions, retirement homes, pensions for the elderly, monasteries and convents, asylums for foreigners, hostels, etc.

An occupied house is a building intended for living in which at least one person must have a usual residence.

An unoccupied house is a building intended for living but it is not the place of usual residence for any person. The number of unoccupied houses includes all buildings with dwellings, and any buildings with collective living quarters that do not contain dwellings if intended for living. Unoccupied houses without dwellings or buildings providing just short-term accommodation (hotels, tourist housing, hospitals, etc.) are not included in the number of unoccupied houses.

Categories of type of building include:

• Family house – a house with a maximum of three separate dwelling units and a prevailing purpose of use is intended for living. Family houses could be detached houses, semi-detached (two family houses built on adjacent lots and structurally connected by a shared wall) and row houses (at least three family homes joined within one circumferential wall). One to three-dwelling houses with a different prevailing purpose of use are not included here.
• Apartment building – a building that has four or more dwelling units usually accessed along a common hallway or stairwell, a prevailing purpose of use is intended for living, regardless of the number of floors. Four or more-dwelling houses with a different prevailing purpose of use are not included here.
• Other buildings – these are all other types of buildings that are not family houses or apartment buildings.

The owner of the house is a natural or legal person, or a combination of both. The data on the ownership structure of the housing stock was taken from the data of the Cadastre of Real Estate valid as of 26 March 2021. The form of ownership is decisive, not the number of owners. The type of owner - natural person - includes cases of multiple co-owners of the house if they are natural persons (e.g. community of property). Co-ownership of dwellings (units) includes only cases where the whole house is co-owned by natural or legal persons who are registered in the Cadastre of Real Estate as owners of specific defined units of the type dwelling or group of dwellings. The type of owner - other legal entity - is found for houses belonging to legal entities other than housing associations, municipalities or the state. Combination of owners includes other cases of co-ownership of a house by several owners of different types who are not at the same time listed in the Cadastre of Real Estate as owners of units (e.g. natural persons and other legal persons, municipalities and housing associations, etc.).

Period of construction or reconstruction
The period of construction or reconstruction is defined as the period when the house was completed and handed over for use (final inspection), or when significant reconstruction took place in connection with the modernization of dwellings or the addition of new floors or dwellings, which required final inspection.

Materials of the building
The materials of the building are load-bearing walls of a house that support the ceilings and roof; these are generally all external walls (except for framed structures). In determining the predominant material of the building, the materials of foundations or partitions are not taken into account. The category 'stone, bricks, blocks' also includes combinations of these three materials.

The type of sewage disposal system shows whether the house has a domestic connection to the public sewage disposal system, its private sewage disposal plant, cesspit, sump or septic tank, or whether the house is without sewage disposal system (direct waste to the ground or watercourse). The decisive criterion for categorization is the method of disposal of sewage, not rainwater.

The lift in the house characterizes the equipment of the house with a passenger lift (a lift usable for transporting people). If there is only a freight lift in the house which cannot be used by the occupants of the dwellings on a regular basis (e.g. in service buildings), the house is classified as 'without lift'.

Central remote heating is a heating installation outside the building, usually for more houses.

Central house heating is a heating installation in the building, usually used for heating in 2 or more dwellings in the house.

Houses without central heating are houses with neither central remote heating nor central house heating. Each dwelling could be heated by central dwelling heating with own source only for the dwelling or other types of heating or without any heating.

Note: All percentage indicators refer only to houses with the identified characteristics.

The results of the 2021 Census are, as in the case of the 2011 Census, processed and published for the usual resident population, or classified according to the usual place of residence. The data of the two Censuses are therefore methodologically comparable.

In contrast, in the previous Censuses in 1961–2001, all processing and publication of results was carried out according to the place of permanent residence, or according to the place of long-term residence. Comparability with data from these earlier Censuses is therefore limited. This is because the processing of data by place of usual residence is reflected in all substantive areas of the data processed. It is determinant both for territorial identification and classification, for the treatment of households, for the determination of dwelling occupancy and for the treatment of characteristics with territorial links or address comparisons, such as residence one year prior to the Census, residence at the time of birth and commuting to the place of work or school.

The concept of registered residence in the 2021 Census corresponds to the concept of permanent or long-term residence in the 2011 Census. It includes permanent residence of a Czech citizen, permanent residence of a foreigner and various types of long-term residence of a foreigner registered in the systems of the Ministry of the Interior.

Data on citizenship are generally published in the 2021 Census for all inhabitants of the Czech Republic according to one citizenship, unless otherwise stated. Persons with dual or multiple nationality derive this single (main) citizenship in the following order: Czech Republic, another EU Member State, another country in Europe, another country outside Europe. In the 2011 Census results, data for persons with single and dual citizenship were reported separately, with the dual citizenship figure including only the combination of the Czech Republic and other country.

The ethnicity data in the 2021 Census were processed for combinations of all separately coded ethnicities in addition to the one declared ethnicity. In the 2021 Census outputs, ethnicity data are preferably reported in the new concept – the total numbers of all persons (with one or two ethnicities) who declared a given ethnicity, either as a single ethnicity or in combination with another ethnicity. Therefore, persons who reported two ethnicities are accounted in the data for both ethnicities. In the 2011 and earlier Censuses, only data for selected combinations of ethnicities were processed; therefore, comparable data of this type cannot be obtained from previous Censuses, even though the methodological approach to the ethnicity question was the same.

Also, language (mother tongue) data were processed in the 2021 Census for combinations of all separately coded languages in addition to individual languages. In the 2021 Census outputs, mother tongue data are preferably reported in the new concept – the total numbers of all persons (with one or two mother tongues) who reported the language, either as the only language or in combination with another language. Persons who reported two mother tongues are thus counted in the data for both languages. As in the case of ethnicity, only data for selected combinations of languages were processed in the 2011 and earlier censuses; therefore, comparable data of this type cannot be obtained from previous censuses, even though the methodological approach to the mother tongue question was the same.

Compared to the 2011 Census, data on religious belief in the 2021 Census were separately collected and published for an expanded list of specific churches, movements, religious societies, and denominations, including categories for belief entries such as atheism, agnosticism, and animism. Persons who indicated that they were believers belonging to a church, religious society, etc., but did not specify a particular church, society or movement are listed in the results in a separate category “Believers belonging to a church, religious society or movement – church, religious society or movement not stated”. In the 2011 Census results, these persons were included in the category “Believers – not affiliated to any church or religious society”.

The highest educational attainment was categorized in the 2021 Census to allow the data to be converted to the corresponding levels of the current ISCED 2011 (International Standard Classification of Education) classification or to data comparable to the 2011 Census results. The “upper secondary continuing/short-cycle” and “post-secondary non-tertiary education” differentiated in the 2021 Census were surveyed as a single category “upper secondary (including post-secondary education)” in the 2011 Census. Similarly, the categories “conservatoire (with graduation)” and “post-secondary professional education (DiS.)”, surveyed separately in the 2021 Census, were included in the 2011 Census in the common group “higher vocational education (with graduation)”.

Highest educational attainment in the 2021 Census according to the ISCED 2011 classification

The terminology in the labour force status (economic activity) data has changed in line with international methodology. In the 2021 Census, the term “labour force“ is used for persons previously referred to as “economically active persons“ and “persons outside the labour force“ instead of “not economically active persons“.

In the 2021 Census, in contrast to the 2011 Census, in addition to categorizing a person according to labour force status, the Census form also asked for at least one hour of work per week and also used data on economic activity from administrative sources. Therefore, the labour force status data from the 2011 and 2021 Censuses are not fully comparable.

In the 2021 Census, the category “persons on parental leave” was newly surveyed. In the 2011 Census, these persons could be included in different categories - as persons with own source of livelihood (with parental allowance), or as homemakers and other dependent persons. Compared to the 2011 Census, the 2021 Census no longer distinguishes the category “unemployed seeking first employment”; only data for the total unemployed is available.

Data on occupation, status in employment and branch or of economic activity were collected in the 2021 Census only for persons employed according to their current main occupation. In the 2011 Census, the data was also collected for the unemployed according to the last occupation held.

The Census 2021 status in employment data no longer distinguish between the categories „members of production cooperatives“ and „contributing family workers“.

The place of work or school and follow-up commuting data are tracked in Census 2021 for employed (working) students by workplace, as for other employed. However, in the 2011 Census, students who were also working while studying reported data on school location and commuting to school. The comparability of commuting data is also limited due to other methodological changes.

The frequency of commuting to work and school was only observed for inter-municipal commuting in the 2011 Census, and also different categories were surveyed than in the 2021 Census.

A maximum of three modes of transport could be identified as the means of transport used to travel to work or school in the 2011 Census without distinguishing their importance. In the 2021 Census, on the other hand, the main mode of transport and a maximum of two complementary modes of transport were collected separately.

The methodology of deriving data for housekeeping households on the basis of the usual place of residence of persons living and running the household together was maintained in the 2021 Census. However, information on relationships between persons was collected in a different way on the Census form (full relationship matrix) compared to the 2011 Census and data from administrative sources were also used. In addition to obtaining more accurate data, this may have affected the comparability of the data with the 2011 Census results.

The household of grandparent-partners with grandchildren is included in the 2021 Census as family households – one-couple families. In 2011, these cases were in the category of non-family multiperson household – grandparent/grandparents with grandchildren.

Data on size of the dwelling (floor space and number of rooms) were collected in a different, simplified way in the 2021 Census than in 2011. In the 2021 Census, only the total area of the dwelling was collected, not the useful floor space nor the area of each room type.

A room in the 2021 Census is a room intended for living purposes, with an area of 4 square metres or more. The number of rooms includes the kitchen if it is a separate room. The kitchen or kitchenette equipment of the dwelling was therefore surveyed separately. In the 2011 Census, a room with an area of 8 square metres or more was considered a standard living room, smaller living rooms with an area of 4 to 8 square metres were surveyed separately, and the distinction between kitchen and kitchenette was different.

In the data on the availability of piped gas in the dwelling, the “no gas” category from the 2011 Census corresponds to the sum of the “gas bottle only” and “no piped gas in the dwelling” categories in the 2021 Census.

Compared to the previous Census, in the data on piped water in the dwelling and in the house there is a new category “both from supply network and private source” in the 2021 Census.

In the data on heating of the dwelling, the category “central dwelling heating” is defined differently in the 2021 Census. The location of the source is not decisive, but important is the fact that it serves only the particular dwelling and can be managed directly by the dwelling user. Until 2011, the category “central dwelling heating – heater inside dwelling”, where the source (boiler) is located directly in the housing unit was used. The different treatment for family houses with 1 dwelling represents a significant difference between the 2011 and 2021 Censuses in the data for the categories “central house heating” and “central dwelling heating”.

The source of energy used for heating was surveyed in more detail in the 2021 Census; in addition to the expanded list of distinguished categories, the main source of energy and up to two additional secondary sources of energy were surveyed.

The location of the dwelling in the house indicates the floor on which the (main) entrance door to the dwelling is located in the 2021 Census. In the 2011 Census, for a dwelling located on more than one floor was reported the lowest floor, except for the special category "ground floor and 1st floor", mainly used for family houses.

The occupancy of houses and dwellings in the 2021 Census is derived from the number of persons usually resident as in the 2011 Census, but the reasons for non-occupancy (vacancy) are no longer collected.

In the 2021 Census, the number of dwellings was used to distinguish the type of building as family house or apartment building, and the number of floors was not taken into account as in the 2011 Census.

In the 2021 Census, an indication of the type of heating of the house was derived from the data on heating of the dwellings in the house. Compared to the 2011 Census, it is limited to the central heating survey, the energy source for the boiler room in the house is not distinguished.