Definitions and explanations for common Census terms

First off, this package uses a couple of semi-official terms to make it easier to unequivocally identify certain parts of an aspect. When we are talking about a

feature, we talk about an indicator aggregated to grid cells, e.g., age or the number of dwellings.
category, we talk about the discrete classifications of features, e.g., ages 10 to 19, 20 to 29, 30 to 39, etc.
Both feature and category have to be provided to uniquely identify a dataset.

This documentation is a collection of definitions as they are provided by the Federal Statistical Office of Germany.

Source

Translated and slightly edited version of the dataset descriptions of the Zensus 2022 and Zensus 2011 gridded datasets by the Federal Statistical Office of Germany.

Building year

This characteristic indicates the year of construction of a building with living space in microcensus classes on the respective census reference date. The year of construction refers to the year in which the building was completed. In the case of conversions, extensions and additions to the house, the original year of construction of the building applies. In the case of completely destroyed and rebuilt buildings, the year of reconstruction is taken as the year of construction.

Building classifications

The census distinguishes three types of building classifications. Because they are very close terminologically, they need clarification:

Building size

Originally called "building type size" (Gebäudetyp-Größe), this classification provides information on the building type in relation to its size. Categories range from detached single-family buildings to multi-story multi-unit buildings.

Building type

Originally called "building type" (Gebäudeart), this classification provides information about the residential use of residential buildings. It distinguishes buildings based on how much space is used for residential purposes. Categories include:

Buildings with living space: Permanent buildings which are either fully or partially reserved for residential use by households. This also includes buildings used for administrative or commercial purposes if they contain at least one dwelling used for residential purposes. Buildings with living space are divided into residential buildings and other buildings with living space.
Residential buildings: Buildings in which at least half of the total usable floor space is used for residential purposes. Residential buildings also include dormitories (where residents run their own household).
Dormitories: Dormitories are residential buildings that primarily serve the housing needs of certain groups of the population (e.g. student residences, retirement homes). Dormitories have common rooms. Residents of dormitories run their own households.
Other buildings with living space: Buildings in which less than half of the total floor space is used for residential purposes, e.g. because the building is predominantly occupied by stores or offices.

Building design

Originally called "building type construction design" (Gebäudetyp-Bauweise), this classification specifies the morphological design of a building, i.e. whether it is detached, semi-detached, terraced or something else.

Citizens / Citizenship

Persons with German citizenship are counted as German citizens. When assigning citizenship, a distinction is made between persons with German and non-German citizenship. Persons with a German citizenship are considered to be German, regardless of the existence of other citizenships.

Members of the German Armed Forces, police authorities and the Foreign Service working abroad and their families residing there are not included in this analysis, as they cannot be assigned regionally at grid cell level in Germany.

Core family

This characteristic indicates the type of core family according to national typification, i.e. according to the reference person principle, taking into account secondary residents. A core family consists of two or more persons belonging to the same private household and is made up of the reference person of the private household - a central person of the private household defined by age, marital status and gender - and at least one other person, e.g. the partner or a child of the reference person. This family concept restricts relationships between ancestors and descendants to direct relationships (first degree), i.e. relationships between parents and children. Only one core family can exist in a household. Other persons living in the household are not assigned to a core family. A household without a core family is possible.

The type of core family depends on the type of couple relationship or the gender of the single parent, and on the presence and age (under or over 18) of children. The term marriage is not differentiated according to the gender of the married persons. Persons in shared accommodation are not included here, only persons who have their own household.

A range of terms relate to core families:

A couple comprises of married couples, couples in a registered civil partnership and couples in a non-marital partnership who live together in a private household.
A married couple is a couple married according to the legal marital status on the reference date and living in a private household.
A registered civil partnership (ELP) is a legally recognized same-sex couple in a private household according to the legal marital status on the reference date.
A non-marital partnership (NELG) is a mixed-sex couple in a private household who were not married to each other according to their legal marital status on the reference date.
A single mother or a single father is a parent without a partner with at least one child within a private household.
A child is a biological son, stepson or adopted son or a biological daughter, stepdaughter or adopted daughter (regardless of age) whose usual place of residence is in the private household of at least one parent and one parent is the caregiver and/or partner of the caregiver.
A senior is defined as a person who has reached the age of 65 on the census date.

Dwelling

A dwelling is defined as rooms that are closed off from the outside, intended for residential purposes, usually located together, which enable the management of a separate household and are not used entirely for commercial purposes.

A dwelling does not necessarily have to contain a kitchen or kitchenette. Apartments have their own entrance directly from the outside, from a stairwell or a vestibule. However, a dwelling may also include basement or floor rooms (e.g. attics) that are developed for residential purposes outside the actual end of the dwelling.

Floor space

To determine the floor space, the following areas are taken into account:

full: floor areas of rooms or parts of rooms with a clear height of at least 2 meters.
half: floor areas of rooms or parts of rooms with a clear height of at least 1 meter but less than 2 meters; unheatable observatories, swimming pools, and similar rooms closed on all sides.
generally a quarter, but no more than half: areas of balconies, loggias, roof gardens, terraces.

Foreigners

Persons with a non-German nationality are counted as foreigners. When assigning nationality, a distinction is made between persons with German and non-German nationality. Persons with German citizenship are considered German, regardless of the existence of other citizenships.

Household

A private household consists of at least one person. This is based on the "concept of communal living": all persons who live together in dwelling, regardless of their residential status (sole residence, main or secondary residence), are considered members of the same private household, meaning that there is one private household per occupied dwelling. There is a maximum of one core family in a household. Other persons living in the household are not assigned to a core family.

Heating type

The characteristic reflects the type of heating in the building. This evaluation is carried out for dwellings. The predominant type of heating in the building is broken down according to which spatial unit (district, building block, building, dwelling, room) is heated by the heating system. In passive houses, systems for heat recovery/controlled ventilation systems are considered "heating" and are assigned accordingly (usually: central heating).

District heating: Here, entire residential districts are supplied with heat from a central district heating plant (so-called district heating).
Self-contained central heating: Self-contained central heating refers to a central heating system for all rooms in a self-contained dwelling, whereby the heating source (for example, gas boiler) is usually located within this dwelling.
Block heating: Block heating is when a block of entire houses is heated by a central heating system and the heating source is located in or on one of the buildings or in its immediate vicinity (so-called local heating).
Central heating: With central heating, all the residential units in a building are heated from a central heating point located within the building (usually in the basement). This also includes heat pumps.
Single or multi-room stoves: Individual stoves (such as coal or night storage stoves) only heat the room in which they are located at any one time. They are usually permanently installed. A multi-room stove (e.g. tiled stove) heats several rooms at the same time (also through air ducts). No heating in the building or in the dwellings

Marital status

The marital status indicates a person's marital status under personal law. The marital status under personal law is determined in accordance with the Personenstandsgesetz (PStG) and the Lebenspartnerschaftsgesetz (LPartG).

The introduction of the right to marriage for persons of the same sex (Eheöffnungsgesetz) has allowed same-sex couples to marry since October 1, 2017. The establishment of new registered civil partnerships under the Lebenspartnerschaftsgesetz (LPartG) has no longer been possible since October 1, 2017. Unless existing civil partnerships are converted into a marriage, registered civil partnerships remain in place.

Net rent

The average net rent per square meter is the ratio between the total rent per square meter of the dwellings and the total number of dwellings. The calculation is made for rented dwellings in residential buildings (excluding dormitories). Dwellings not rented out are excluded from the calculation.

Ownership

Ownership is divided into home ownership and property ownership. Home ownership determines who is entitled to ownership of a dwelling in a building divided according to the Wohneigentumsgesetz (WEG) while property ownership determines who is entitled to ownership in a building. Owners can be private individuals or legal entities.

The ownership rate represents the share of owner-occupied dwellings in all occupied dwellings. Not taken into account: Vacant dwellings, vacation and leisure dwellings and commercially used dwellings. The calculation is made for dwellings in residential buildings (excluding halls of residence).

Place of birth

Persons born up to August 2, 1945 in former German eastern territories within the borders of Germany in 1937 are not counted as born abroad, but are assigned the German state code. If the place of birth is not within these borders, the current state code is assigned. Places of birth in countries that have merged into other countries, such as the Soviet Union or Yugoslavia, are assigned to the countries that exist today wherever possible.

EU27: Comprises the member states of the European Union as of 15 May 2022, previously last amended by the UK's withdrawal in 2020. Persons born in Czechoslovakia are also included in "EU27 country (as of 2020)" with the current country codes. Croatia is also included here following its accession to the EU on July 1, 2013.
Other Europe: Includes the Russian Federation and Turkey as well as other current country codes of the former Soviet Union and the former Yugoslavia. Great Britain is assigned here following its withdrawal from the EU.
Other World: Includes all other countries. This category includes other current country codes of the former Soviet Union that were not assigned to "Other Europe".
Other: Includes "Not specified".

Residents

Each resident is assigned to an address and thus to a grid cell with a side length of 100 m, 1 km or 10 km. Members of the German Armed Forces, police authorities and the Foreign Service working abroad and their families living there are not included in this analysis, as they cannot be assigned regionally at grid cell level in Germany.

Room

A room is either a living room, dining room, bedroom or other separate room (e.g. habitable cellar or floor rooms) of at least 6 square meters in size as well as self-contained kitchens, regardless of their size. Bathrooms, toilets, hallways and utility rooms are generally not counted. A living room with a dining area, sleeping alcove or kitchenette is to be counted as one room. Accordingly, dwellings in which there is no structural separation of the individual living areas (e.g. so-called "loft dwellings") consist of only one room.

Source of heating

The characteristic shows the energy source of the heating in the building. This evaluation is carried out for dwellings. Energy source used to heat the building. If there are several energy sources in the building, it is the one that heats the largest part of the living space. In passive houses, the residual heat requirement is covered by an additional source, which is specified here.

Gas
Heating oil
Wood, wood pellets
Biomass (excluding wood), biogas: All organic substances produced by plants or animals from which energy can be obtained by burning. Energy can be obtained through combustion. This includes straw, organic waste or liquid manure (excluding wood). Biogas is produced during the fermentation of biomass and is also classified here.
Solar/geothermal energy, environmental heat, exhaust air heat: Solar energy as well as energy from water, air and earth is obtained here with the help of collectors, heat pumps and heat exchangers. This also includes heat obtained from the exhaust air of buildings (so-called exhaust air heat).
Electricity (without heat pumps)
Coal
District heating (various heating sources)
No energy source (no heating)

Vacancy

The vacancy rate (dwellings) represents the ratio of vacant dwellings to all occupied and vacant dwellings. The market-active vacancy rate represents the proportion of vacant dwellings that are available again within three months as a percentage of all dwellings in residential buildings. Not taken into account: Vacation and leisure dwellings as well as commercially used dwellings. The calculation is made for dwellings in residential buildings (excluding halls of residence).