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Population and housing census, dwellings (discontinued)19 November 2011

Content

About the statistics

Definitions

Name and topic

Name: Population and housing census, dwellings (discontinued)
Topic: Population

Responsible division

Division for Population Statistics

Definitions of the main concepts and variables

Definition of units

Resident person. The census comprises all persons that according to the population register were residents in Norway on 19 November 2011. The Population Registration Act of 16 January 1970 (with later amendments) and its provisions, define persons that are considered resident in Norway and where their address is to be. The total number of persons resident in a region is the total population.

Couple. Two persons are considered a couple when they are registered as resident in the same household and are married to each other, are registered partners or cohabitants, i.e. living together without being married or having a registered partnership. To be classified as a cohabiting couple in the statistics, the persons must live in the same dwelling and in addition be of opposite sex and either have children in common, have been classified as cohabitants in the 2001 census or have been classified as a cohabitant couple in the system for data processing, control and revision described in 'Control and revision'. The data quality is not good enough to identify same sex cohabitants, and statistics for this group is accordingly not published.

Divorced and separated couples registered as resident in the same dwelling are considered a couple when they fulfil at least one of the requirements above. Divorced couples are in those cases classified as cohabiting. Separated couples living together are classified as married couples in the household statistics, because they legally are still considered to be married.

Family. A family consists of persons resident in the same dwelling and being a couple and/or parent and child (regardless of the child's age). At most, a family may consist of two subsequent generations and one couple only. This means that persons that are married or cohabiting and/or are living with their own children, do not belong to their parents' family. When persons that have previously been married are living with their parents, this is regarded as two families. In Norwegian statistics single persons are also considered a family, meaning that all persons are part of a family. In international statistics persons living alone are not considered to be a family (family nucleus).

Household. A household consists of persons that according to the population register are resident in the same housing unit (private dwelling or institution). These households are known as dwelling households. The census statistics does not include any information on housekeeping units, i.e. persons living in the same dwelling with joint board. A private household comprises persons resident in the same dwelling, where this dwelling is not an institution. An institutional household comprises persons who have board, lodging, care or nursing at an institution. Employees that are resident in an institution are always considered resident in a private household.

Dwelling. A dwelling is a housing unit with one or more rooms that has been built or rebuilt for the purpose of being used as a round-the-year dwelling for one or more persons. It must be possible to have access to the room (-s) without having to go through another dwelling. As dwellings are counted both conventional dwellings with at least one room and kitchen, and single rooms with separate entrance and access to water and toilet inside the living quarters.

Occupied dwelling. An occupied dwelling in the 2011 census is a dwelling where at least one person is resident according to the population register. Dwellings used only by persons registered as residents on a different address, for instance students and weekly commuters, are not classified as occupied. The same is true for dwellings for seasonal or secondary use and dwellings used by persons not registered as resident in Norway, for instance persons staying temporarily in the country.

Variables - demography and place of residence

Age. In the 2011 Census, persons are grouped according to age at census date (19 November). This definition complies with the EU regulation. In previous censuses, persons were grouped according to age at the end of the year (31 December). This variable is also produced in the 2011 census, but it is not used for publishing statistics.

Residential address. In the 2011 census, this is the address where the individual person was registered as resident on 19 November 2011. The main rule in population registration is that a person is to be registered as resident at the address where the person spends the majority of his or her daily night-rest. However there are some exceptions, the most important being that unmarried students may choose whether they want to be registered at their parents’ address or at the address at their place of study. Moreover, married persons who are de facto living in a home for the elderly shall as a main rule be registered with their spouse if he/she is living in a private household. Married persons and persons with their own children in the same household are to be registered as living with their spouse and/or children even though they might be e.g. weekly commuters. Persons that according to the population register have no fixed abode are counted in the municipality where they previously resided. In tables by basic statistical unit and statistical tract, these persons are classified as unknown. The same applies in classifications by densely/sparsely populated area.

In the 2011 census persons that according to the Population register of Svalbard are residing in Longyearbyen or Ny-Ålesund, are counted as residents there. The address in Svalbard then replaces the address in the Central population register in the census file.

Family variables

Cohabitation arrangements. Persons are classified as living in a married couple, a cohabiting couple or not in a couple. Couples are classified as being married or cohabiting (for definition of couple, see Definitions of the main concepts and variables).

Number of children in the family comprises all persons below 18 years who are registered as residents with the family of at least one of their parents. Persons who are married or cohabiting and/or have their own children do not belong to their parents’ family. Biological children, adopted children and stepchildren are included, but not foster children.

Household variables

Household status describes the type of household in which a person lives and his/hers position in the household. The main division is between persons living in a private household or not in a private household. Persons in private household are classified according to the number of families in the household (one family or two-or-more families). Persons in one-family households are classified as either living alone or living with others. Persons living with others are classified as living in a couple (as married or cohabiting), as a lone parent or as a son/daughter in the family.

Persons not living in a private household should in principle be classified either as living in an institution or with household status “unknown”. Given the data quality this subdivision is rather uncertain, especially on municipality level. Statistics Norway therefore has decided to publish figures for persons not living in private households with no such subdivision. In total 52 500 persons belong to this group and it is estimated that a little more than half of them are living in institutions. Only persons registered as living in an institution belong to this group. Persons that are de facto living in an institution, but have a spouse living in a private household, are in some cases registered as living with the spouse, i.e. in a private household.

As the definition of family in Norwegian statistics is somewhat different from the definition used in international statistics (see 'Definitions of the main concepts and variables), the classifications by household status are not identical. However, statistics according to the international standard will also be produced from the Norwegian census.

Type of household is classified according to Standard classification of households 2006 (see Standard classifications). Households are classified by the number of families in the household (one family or two-or-more families) and as families with or without children (as defined in Number of children in the household.). For comparison with international statistics, see Household status.

Size of household is the number of persons resident in the household at census time. Only person registered on the residential address are counted.

Number of children in the household is the aggregated number of children in all families belonging to the household. Persons below 18 years who are registered as living with other adults than their parents are in this context not counted as children in the household.

Tenure status of household. Owners comprise both homeowners (owner-occupied dwellings) and cooperative ownership. When none of the household members is the owner of the dwelling the household is classified as renting the dwelling (see Control and revision).

Housing variables

Housing arrangements. The resident population is classified as living in a conventional dwelling or not. Persons not living in a conventional dwelling are either registered as living in a collective living quarter or housing arrangements are not stated.

Type of building is established according to the function of the building. Combined buildings, for instance combined residential and commercial buildings, are classified by the function that occupies the main part of the utility floor space. Detached houses include farm houses and also holiday houses with at least one person registered as resident. Houses with two dwellings can be horizontally or vertically divided. Row houses, linked houses and houses with three dwellings or more also include terraced houses. Multi dwelling buildings are large residential buildings with two ore more floors and at least five dwellings. Residences for communities include service residences for the elderly and other social groups and students homes, but not institutions.

Year of construction is the year the building was ready to move into. In buildings with more than one dwelling, where the dwellings are being occupied gradually, the year of construction is the year when at least half of the dwellings are ready to move in to. In houses that have been renovated, the year of construction is the original year of construction.

Utility floor space is the floor area measured within the outer walls, defined in Norwegian Standard NS 3940 Area and volume calculations of buildings. All types of rooms within the dwelling, also storage rooms, are included. Rooms which can only be accessed by going out of the dwelling, for instance storage rooms, are not included.

Number of rooms in the dwelling. A room must satisfy the room requirements of the Building Act and be 6 m2 or more. Kitchens, bathrooms, WCs, utility rooms, corridors etc. are not included.

Kitchen is the part of the dwelling where cooking equipment is installed. The kitchen could be a separate room, however open kitchens are also considered kitchens. If several dwellings have a joint kitchen, e.g. in a block of bed-sits, all dwellings are considered as being without a separate kitchen.

Number of occupants in the dwelling refers to the number of persons registered as residents in the dwelling on census day. Note that according to this definition, the number of occupants in a region only comprises persons living in private households/conventional dwellings. This figure is slightly lower than the total population in the region, which also includes persons not living in private households (institutional households, etc.)

Type of ownership for dwellings is the same tenure status for households, see Household variables.

Number of WCs includes water closets inside the dwelling. WCs outside the dwelling shared by several dwellings are not included.

Position of the dwelling in the building refers to the floor where the entrance of the dwelling is located.

Elevator. The variable provides information on whether an elevator has been installed in the building. Elevator here means passenger elevator, not hoist or stairway elevator installed in detached houses.

Geographical variables

County. The region 21 Svalbard is included in tables by counties even though this region is not a county in the legal sense.

Municipality. The municipality distribution as at 1 January 2012 is used. Per 1 January 2012 the municipalities 1723 Mosvik and 1729 Inderøy were merged to 1756 Inderøy. The region 2111_2112 Longyearbyen and Ny-Ålesund are included in tables by municipality even though this region is not a municipality in the legal sense.

Standard classifications

Classification of region

Classification of county

Classification of municipality

Classification of urban district

Classification of households

Classification of type of building/GAB

Administrative information

Regional level

Most of the census statistics are disseminated on municipality level and on urban districts level for the cities of Oslo, Bergen, Trondheim and Stavanger. Selected statistics will also be disseminated for basic statistical units and statistical tracts.

Frequency and timeliness

Population and housing censuses are conducted every tenth year. In 2011 census day was 19 November.

Dates for releases, see Advance release calendar.

International reporting

Reporting to Eurostat and UN

Microdata

Census micro data without personal identification will be stored in Statistics Norway. Micro data with personal identification will be stored in The National Archives of Norway and will be made available for public use 100 years after the census.

Background

Background and purpose

Statistics Norway conducted a register-based population and housing census on 19 November 2011. The purpose of this nationwide census is to describe how people are living in Norway, and to provide information on population structure and living conditions. Another important goal is to produce statistics for international comparisons.

Population and housing censuses have a long history in Norway. The first census was conducted in 1769 and the 2011 census is the 22nd.

In all previous censuses, questionnaires have been used to collect information; from 1980 on, a combination of data from questionnaires and registers have been used. In the 2011 census, all data are for the first time collected from administrative and statistical registers, and there is no longer necessary to use questionnaires in the census data collection. However, data from the Survey of education taken abroad 2012 is used in the 2011 census. More information, see About the statistics for Education statistics. (hyperkopling til http://www.ssb.no/english/subjects/04/01/utniv_en/)

More information in the census information page. (hyperkopling til http://www.ssb.no/a/english/innrapportering/fob2011)

Users and applications

Census statistics has a wide range of users: Researchers, planners on national and local level, politicians, media and private individuals. The statistics is also used for international comparisons.

Coherence with other statistics

Total population

The 2011 census population on Svalbard only comprises persons registered as residents in Norway at census time. Compared to the annual population statistics on Svalbard, that comprises all residents in the Norwegian settlement and also a population count for the Russian and Polish settlements, the census will give a lower population figure.

The points made in 'Comparability over time and space' also apply when comparing the 2011 census to the annual population statistics.

Households

The data used in the 2011 census is almost the same as for the annual household statistics, but some adjustments have been made. Approximately 13 000 persons who in the annual statistics are counted as members of private households, are in the census classified with “household status unknown”. In the 2011 census 1.1 per cent of the population is classified as not living in a private household, as compared to 0.8 per cent in the household statistics per 1 January 2011. For private households, the portion of couples without children increases from 21.2 to 21.4 per cent, while the portion of one-person households decreases from 39.7 to 39.6 per cent. For other types of households the changes are even smaller. Except for these differences, the comparability with the annual household statistics is good. The data used in the household statistics for 2012 will be adjusted in the same way as in the 2011 census.

The Income statistics for households basically uses the same data as the 2011 census, but the reference date is 31 December every year. However, the definition of households in the income statistics is different from the definition in the census. Students and young employees that have a registered place of residence far away from the place of study/work, is counted in the municipality where they study/work. Furthermore, all persons living in institutions are classified as living in an institutional household, irrespectively of where they are registered as receding. This is a necessary adjustment in the income statistics where the goal is to estimate the economic resources for people living together and sharing income and expenditures. The problem is that for most of the persons in question, the only information available is the municipality in which they live and not the precise address. These address data are sufficient for the income statistics, but the method can not be used in a general household statistics were all persons must be linked to a specific residential address and thereby classified correctly according to household characteristics. The number of households in the income statistics is approximately 4 per cent higher that in the census statistics. The income statistics shows more persons living alone, more couples without children and fewer households with children above 18 years than the 2011 census.

Tenure status of households

The percentage of household owning their dwelling is approximately 5 per cent lower in the 2011 census than according to the Survey of living conditions. The changes over the last ten years, however, are the same in both statistics. When comparing the statistics one must take into account that the Survey of living conditions is based on interviews and use the housekeeping unit concept and the actual (self declared) residential address.

Dwellings

The annual dwelling statistics published for the years 2006 to 2011 gives the total number of dwellings only and not the number of occupied dwellings. Compared to the annual statistics, the 2011 census shows 48 000 more dwellings, see 'Control and revision'.

In the 2011 census, the total number of dwellings is published by type of building and year of construction only. Classification by type of building is fully comparable with the annual dwelling statistics. The register for real estate taxation as a data source is implemented after the dwelling statistics for 2011 was published. This means that the percentage of dwellings with year of construction unknown, have been reduced. Apart from that, the comparability for year of construction is good. Classification by utility floor space in the 2011 census is less comparable with the corresponding figures in the annual dwelling statistics.

Figures from the 2011 census will be fully comparable with the annual dwelling statistics from 2012.

Legal authority

Statistics Act, §§2-1, 3-2

EEA reference

Regulation (EC) No 0763/2008 of the European Parliament and of the Council.

Production

Population

Only information related to the publishing of housing statistics is mentioned in this section.

The Population and housing census 2011 comprises all persons, including foreign citizens, who were registered as residents in Norway according to the Central Population Register on 19 November 2011, census day.

The census basically comprises all conventional dwellings according to the principles for registration of dwellings in the Cadastre (register on ground properties, buildings, dwellings and addresses managed by the Norwegian mapping authorities). All dwellings, occupied as well as unoccupied, are included. Dwellings used as holiday homes are included when at least one persons is registered as living on the address. More information, see About the statistics for Housing statistics (dwelling stock). (hyperkopling til http://www.ssb.no/boligstat_en/)

Data sources and sampling

All data in the 2011 census are retrieved from administrative and statistical registers. These data are mainly the same as those used in other statistics. Statistics Norway has built up data systems, referred to as statistical registers, in several statistical areas (sectors). These are again based upon one or more administrative data systems that are either administrative registers held by other public authorities or administrative data collected by Statistics Norway.

Population data

The population statistics system at Statistics Norway (BeReg) is the most central register for information on persons, families and households in the census. The main source of data is the Central Population Register (CPR). More information in About the statistics for Population statistics. (hyperkopling til http://www.ssb.no/folkemengde/).

Information on residents in Longyearbyen and Ny-Ålesund is collected from the Population register of Svalbard.

Data on households

The main data source is the population statistics system at Statistics Norway (BeReg). Persons are grouped into families in the population register through allocation of family numbers. Families in the population register comprise married couples with or without children, lone parents with children and persons living alone. In order to produce figures for cohabiting couples and two or more-family households, and hereby all types of families and households, Statistics Norway processes information from the population register. In addition some information from The Cadastre and the business register are used in this process. Data from the same registers are used to identify persons not living in private households (living in institutions, of no fixed abode or address unknown).

For the variables tenure status for households and type of ownership for dwellings, information about owners is retrieved from Statistics Norway’s version of the Cadastre. Information about cooperative ownership is retrieved from a register for real estate taxation.

Data on housing

The housing census is based on information from Statistics Norway’s version of the Cadastre. The main data source is the administrative Cadastre. For information on year of construction, utility floor space and toilet and bathing facilities, supplementary data sources are used. The most important supplementary sources are the register for real estate taxation and data collected in the 2001 housing census.

Geographical information

Information on addresses of residents, dwellings, work places and schools/educational institutions is retrieved from the address section of the Cadastre. This is information on the basic statistical unit, municipality, etc., to which the address belongs and whether the address is located in a densely or sparsely populated area.

The population and housing census 2011 was a full count.

 

Collection of data, editing and estimations

The census is fully register-based and hence there is no separate data collection.

Register data used in statistics are verified and edited to a greater or lesser degree. Variables that are not found in any of the administrative sources are created by combining data from various register sources. Editing is mainly carried out in production of the various subject matter statistics.

Households

Household figures in the 2011 census are produced in the same way as in the annual household statistics. The procedure used is described in About the statistics for household statistics. About the statistics for household statistics The basic principle is that all persons with the same residential address in the population register belong to the same household (see 'Definitions og the main concepts and variables'). However, a household count following this principle gives too few and too large households. Therefore, Statistics Norway has developed a method where information from the census forms in 2001 is used to modify the data from the population register. When members of the original household are not relatives, are not classified as cohabitants and did not move to the dwelling on the same day, households are in some cases divided.

Tenure status and type of ownership

Information on tenure status of households and type of ownership for dwellings is established by combining data on households and dwellings. The household is classified as homeowner if at least one of the household members is registered as the owner (owner-occupied dwelling). If at least one household member is the owner within the framework of a housing cooperative, the household is classified as having a collective ownership. If none of these conditions are met, the household is classified as renting the dwelling.

Consistency between private households and occupied dwellings

According to the definition of a dwelling household, the number of occupied dwellings should be the same as the number of private households, see 'Definitions of the main concepts and variables'. The main principle in the formation of households is that residents and dwellings are matched by using the dwelling address. Due to errors in the data sources, a specific method for harmonizing data on households and dwellings has been developed. The method gives reasonable counts for households and occupied dwellings, but the two populations are not fully consistent. In the statistics, there are 19 000 more private households than occupied dwellings.

The total number of dwellings

In some cases there are more than one household on the dwelling address according to the household data. This indicates that some dwellings are not registered in the Cadastre. For this reason, the statistical population of dwellings have been adjusted by adding 48 000 units. This is done only for detached houses, houses with two dwellings and in none-residential buildings.

Occupancy status for dwellings

The method developed for determining occupancy status gives estimates for the total number of dwellings and the number of occupied dwellings, but no independent estimate for unoccupied dwellings. Calculating the number of unoccupied dwellings by simple subtraction, does not give a reliable estimate. For this reason, statistics on unoccupied dwellings is not published in the 2011 housing census.

Information on dwellings

The Cadastre is the main source for information on dwellings, but supplementary sources are used to improve the coverage for dwelling variables, see 'Data sources'. More information in About the statistics for housing statistics. About the statistics for housing statistics. . For the 2011 housing census, new data sources have been implemented, the most important being the register for real state taxation. This means that coverage as well as data quality has been improved, but it may have an impact on comparability with previous censuses, see 'Comparability over time and space' and 'Coherence with other statistics'.

Census statistics are produced directly from the individual register data.

 

Confidentiality

Small area statistics is an important part of censuses, but the statistics shall not provide information that can be traced back to individual persons. In respect of the protection of privacy, many of the tables have been adjusted in order that combinations of variable figures that only occur once or twice should not be identifiable in the tables. In most of the table matrixes at the most detailed level in every region (county, municipality, urban district, basic statistical unit), all figures 1 and 2 are replaced by 0 or 3 (table matrixes affected by this will be marked with foot notes). The figures 0 and 3 also occur naturally, and it should not be possible to see the difference between the two types of 0 and 3. The replacements are done such that there will be only minor deviations at a higher level of aggregation. These deviations will generally be less than errors in the statistics, and will not reduce the utilitarian value of the statistics. When the same table is produced on the basis of two different matrixes, minor deviations may also occur between the tables.

Comparability over time and space

The basis for comparisons is mainly the 2001 census.

Residents in Svalbard

In the 2011 census, persons actually living on the islands of Svalbard are counted there, but in previous censuses they were counted at their place of registered residence. Compared to previous censuses, the 2011 census therefore shows a somewhat smaller population in municipalities where a substantial number of registered residents actually live in Svalbard.

Age

Adapting to the EU regulation, the 2011 census uses age at census date (19 November). In previous censuses, age at the end of the years has been used. In particular, the age group below one year will be larger when using age at census time, since all persons born in the last 12 months are included. When using age at end of the year, only persons born in 2011 will belong to this age group. In the 2011 census the difference is approximately 6 500 persons for this age group.

Households

In the 2001 census household data was mainly based on information from census forms, but in 2011 household data are based on registers only. When the annual, register-based household statistics was established in 2005, the comparability with the 2001 census was assessed to be satisfactory, and data from the 2001 census is also used in producing the register-based household statistics. The 2011 census is based on the same data as the annual statistics: In establishing a method for register-based household statistics, comparability with previous censuses was emphasized. However, in assessing changes from the pervious census, this difference in data collection method should be taken into account.

Tenure status of households

A breakdown of households by tenure status has not been included in the annual statistics. The variable was in the 2001 census based on information from census forms, but in the 2011 census it is register-based. The figures show a small decrease in the percentage of households renting their dwelling from 2001 to 2011. The Survey of living conditions shows approximately the same decrease. In the 2001 census households renting their dwelling was classified as renting from a private individual, from a rental housing company, from the municipality, as a staff dwelling or on other terms. A similar subdivision is not possible in the 2011 census.

Occupied dwellings

In the 2001 census data was collected from households and the number of occupied dwellings was by definition the same as the number of private households. In the 2011 census, separate data on dwellings are retrieved from the Cadastre. Data on households and dwellings have been harmonized, but full consistency between the populations of occupied dwellings and private households was not obtained, see 'Control and revision'. If the same principle as in the 2001 census had been used, the number of occupied dwellings in the 2011 census would have been 19 000 higher.

Partial non-response for dwellings

In the 2001 census, the partial non-response rates varied quite a lot between dwelling variables. For instance, for utility floor space, the none-response was 2.1 per cent and for number of rooms 18.4 per cent. Information from the Cadastre was used to reduce the non-response when possible. All remaining cases of missing values were imputed.

The 2011 census uses the same register-based data as the annual dwelling statistics. In the annual statistics imputation is used, but only on certain conditions. Hence, for most dwelling variables, “not stated” occurs in the statistics. The partial non-response is highest for number of bathrooms and number of WCs (5.8 per cent). For number of rooms the non-response is 4.9 per cent, for year of construction 4.4 per cent, for kitchen 3.6 per cent and for utility floor space 3.1 per cent. There is no non-response for type of building and position of the dwelling in the building. When comparing statistics for 2011 and 2001, it must be taken into account that non-response is handled differently. In some municipalities the non-response in the 2011 census is well above the national level, making comparison more difficult.

Dwelling variables

Different data collection methods in the 2001 census (questionnaires) and the 2011 census (registers) influences on comparability for all dwelling variables. The 2001 census is also a supplementing data source for the statistical version of the Cadastre used as the data source in the 2011 census. Hence, for variables where the 2001 census is the data source for a great portion of dwellings, the accordance will be best. On the other hand, this means that data are less updated.

Type of building is based on registers in both censuses, meaning that the comparability is good. The statistics shows that the number of dwellings in multi-dwelling buildings is increasing most, a development confirmed by both the Building statistics and the Survey of level of living.

Year of construction. Only 6.1 per cent of all dwellings have the 2001 census as data source. The comparability is satisfactory.

Utility floor space. Because data from the register for real estate taxation is frequently used as a supplementing data source, only 3.7 per cent of all dwellings have the 2001 census as data source. Comparisons of figures from the 2001 and the 2011 censuses show that the number of small dwellings (less than 50 square meters) has decreased. For dwellings 80 square meters and larger, the statistics shows a shift towards larger dwellings. The number of dwellings 160 square meter and larger has increased by 40 per cent. Even though a development in direction of larger dwellings is certainly real, the shift is most probably not as great as shown when comparing figures from the two censuses. The reason may be several. In the 2001 census utility floor space may have been under-reported by some households for instance that storage rooms in basements was not included. Furthermore, rooms hired out should according to instructions not be included in the floor space. In the Cadastre such rooms are included unless classified as separate dwellings. In the 2011 census, the use of data from the real estate taxation may have caused some uncertainty. The conclusion is that statistics from the traditional census in 2001 and the register-based census in 2011 is not fully comparable.

Number of rooms. As much as 30.8 per cent of all dwellings have the 2001 census as a data source. The census statistics shows a substantial decrease in dwellings with one room from 2001 to 2011, an increase in the number of dwellings with 2-4 rooms and a smaller decrease in the number of dwellings with 5 rooms or more. Due to high degree of non-response and consequently use of imputation, the figures from 2001 are less reliable. When comparing figures from 2011 and 2001 the differences in data collection method must be taken into consideration. However, figures are considered more comparable than for utility floor space.

Bathroom and WC. The portion of dwellings in the 2011 census using the 2001 census as data source is 35 per cent for both variables. In the 2001 census form there were questions on number of bathrooms and number of WCs and “none “ was an option. The statistics shows that 97 per cent of all dwellings had both bathroom and WC. In the register-based data used in 2011, it is not possible to distinguish between dwellings with no bathroom /WC and dwellings where the number is not known. The 2011 census then shows that the portion of dwellings with bathroom and WC is 94 per cent. This percentage is too low compared to the 2001 census.

Kitchen. The portion of dwellings in the 2011 census using the 2001 census as data source is 30.8 per cent. Comparability between the 2001 and the 2011 census are satisfactory.

Housing variables in the 2001 census not included in the 2011 census

Some variables that in 2001 was collected by questionnaires, is not available from registers. Hence, they are not included in the 2011 census. These variables are:

Accessibility for wheel chair user

Systems for heating

Sources of energy for heating

Type of sewer system

Access to garden

Balcony veranda, terrace

Garage, car port, parking space

Accuracy and reliability

Sources of error and uncertainty

Measurement and processing errors

The 2011 census uses the same register-based data as the different subject matter statistics published by Statistics Norway. For descriptions of measurement and processing errors, see About the statistics for the relevant subject matter statistics.

Tenure status of household

The method used for producing data on tenure status only covers 85 per cent of all household. For the remaining 15 per cent the values are imputed by using a nearest neighbour method. In some municipalities a small number of households will have the imputed value “cooperative ownership” even if housing cooperatives do not exist in the municipality.

Coverage for the total population

According to the EU regulation, the population is defined as all persons who have been living in the country for 12 months ore more at census time, or if not meeting this criterion, have the intention to stay for at least 12 months. Compared to this definition, a register-based census will have coverage errors.

A person legally living in Norway will indeed have self-interest to register as a resident person in the population register. For persons emigrating, de-registration will not be as important, meaning that some persons that no longer live in Norway most probably incorrectly are included in the census population. This results in over-coverage. On the other hand there will at any time be some persons staying in the country that are not included in the census population. This applies to all illegal immigrants, but also to asylum seekers that have not obtained a residence permit. This results in under-coverage.

Estimates of over- and under-coverage will be reported in 2013. However, compared to the total population size, coverage errors most certainly are of a very small magnitude.

Households

A correct distribution of households in the 2011 census is very much dependent on the existence of unique dwelling addresses in the population register. Dwellings in multi-dwelling buildings need to have a unique dwelling number in addition to the street address. In 2011 the coverage rate for unique addresses is satisfactory, more than 95 per cent. However, there is evidence that for some persons, the dwelling address is incorrect.

Another quality problem is delayed and missing notices of removal to the population register. In cases where a family in fact has moved from a dwelling (but without reporting the removal to the population register) and a new family has moved in, the register data will show two families living in the same household. This type of error also occurs when persons are moving abroad and especially if they are leaving the country temporarily only.

Furthermore, there may exist dwelling that are not properly registered in the Cadastre, especially in detached houses where a one-room flat may be missing. In such cases, the register data will show that persons are living in the same dwelling, even if they in facts have separate dwellings and belong to different households.

The method used for producing household statistics will correct for most errors of the types mentioned above, see About the statistics for household statistics . Furthermore, in establishing the data for the 2011 census, the populations have been somewhat adjusted. The number of private households has been reduced as approximately 13 000 persons have been classified in “household status unknown” (most of them formerly classified as living alone). The original population of dwellings has also been adjusted by adding 48 600 dwellings for statistical use, mainly in detached houses. This improves the quality of household data in the census. However, the errors mentioned introduce an element of uncertainty in the household statistics, especially in cases where persons not belonging to the same family are registered on the same address. It may then be difficult to judge if they should be classified as a two-or-more family household or as several separate households.

Households in Svalbard

Only persons registered as resident in Norway are included in the census, having an influence on the household distribution in cases where persons included in the census are living together with persons staying temporarily in the country (and hence are not registered as residents). For example, a resident person living with a spouse or a cohabitant not registered as a resident would be classified as living alone or as a lone parent. In most municipalities this error is of a very small magnitude. In the settlements on Svalbard, however, where such cases occur more frequently, this type of error must be taken into account.

Total number of dwellings and occupied dwellings

The difference between published figures for the total number of dwellings and occupied dwellings should according to the definition be unoccupied dwellings. Due to data quality problems, such an interpretation of this difference is not advisable, see 'Control and revision'.

According to the definition of dwelling household, the number of occupied dwellings should be the same as the number of private households. The method used for harmonizing data on households and dwellings does not give full consistency between the two populations. In the statistics, there are 19 000 more private households than occupied dwellings, see 'Control and revision'.

Utility floor space and number of rooms

In the 2001 census data was edited to obtain consistency between utility floor space and number of rooms for each dwelling. Data in the 2011 census is not edited in this way. Hence, combinations of values that are not logical may occur, for instance dwellings with one room and large floor space or dwellings with many rooms and small floor space. In general, such inconsistencies are not of great importance, but for a few municipalities the effect may be substantial.