Demographic and Social Statistics

B. Construction material of outer walls (paras. 2.304-2.306)

This topic refers to the construction material of external (outer) walls of the building in which the sets of living quarters are located. If the walls are constructed of more than one type of material, the predominant type of material should be reported. The types distinguished (brick, concrete, wood, adobe and so on) will depend upon the materials most frequently used in the country concerned and on their significance from the point of view of permanency of construction or assessment of durability.

In some countries, the material used for the construction of roofs or of floors may be of special significance for the assessment of durability and, in such cases, it may be necessary to collect information on this as well as on the material of the walls. Durability refers to the period of time for which the 90 structure remains habitable, subject to regular maintenance. A durable structure is one expected to remain sound for a considerable period of time. Countries may wish to define the length of the period, for example, 15 or 20 years. Durability does not depend solely on the materials used in construction, since it is also affected by the way the building was erected, that is to say, the consideration whether it was built according to construction standards and regulations. Recently, technological developments in treating traditional building materials, such as bamboo, have extended the durability of those materials for several decades. Construction material of outer walls may be considered an indicator of the building’s durability.

C. Year or period of construction (paras. 2.307-2.311)

This topic refers to the age of the building in which the sets of living quarters are located. It is recommended that the exact year of construction be sought for buildings constructed during the intercensal period immediately preceding if it does not exceed 10 years. Where the intercensal period exceeds 10 years or where no previous census has been carried out, the exact year of construction should be sought for buildings constructed during the preceding 10 years. For buildings constructed before that time, the information should be collected in terms of periods that will provide a useful means of assessing the age of the housing stock. Difficulty may be experienced in collecting data on this topic because in some cases the occupants may not know the date of construction.

The collection of data for single years during the intercensal period is seen as a method of checking construction statistics for deficient coverage and of integrating more closely integrating the housing census with current housing statistics.

The periods should be defined in terms of events that have some special significance in the country concerned; examples would be the period since the Second World War, the period between the First World War and the Second World War; the period before the earthquake, flood and so forth. Three age groups may be regarded as constituting a minimum classification. The total period covered by the age groups and the number of groups distinguished will depend upon thematerials and methods of construction used in the country concerned and the number of years that buildings normally last.

Where parts of buildings have been constructed at different time, the year or period of construction should refer to the major part. Where living quarters comprise more than one building (living quarters with detached rooms, for example), the age of the building that contains the major part of the living quarters should be recorded.

In countries where a significant number of households construct their own living quarters (countries with large nonmonetary sectors, for example), it may be useful to include an additional question that will distinguish the living quarters according to whether or not they were constructed by the household(s) occupying them. The information should refer only to living quarters constructed during the preceding intercensal or 10-year period, and it should be made clear in formulating the question that it refers to living quarters constructed mainly by households (with or without the help of other households in the community) and not to construction executed by enterprises on behalf of households.

D. Location of living quarters (paras. 2.312-2.319)

A great deal of information relevant to the location of living quarters is contained under the definition of "locality" and "urban and rural". It is important for those concerned with carrying out housing censuses to study this information, because the geographical concepts used in carrying out a housing census to describe the location of living quarters are extremely important both for the execution of the census and for the subsequent tabulation of the census results. When the housing census is combined with, or closely related to, a population census, these concepts need to be carefully considered and coordinated so that the geographical areas recognized in carrying out the two censuses are of optimum value for both operations.

Information on location should be collected in sufficient detail to enable tabulations to be made for the smallest geographical subdivisions required by the tabulation plan. To satisfy the requirements of the geographical classifications recommended in the tabulations in annex II to this publication, information is needed on whether the living quarters are located in an urban or rural area, the major civil division, the minor civil division and, for living quarters located in principal localities, the name of the locality

Where a permanent system of house or building numbers does not already exist, it is essential for the census to establish a numbering system so that the location of each set of living quarters can be adequately described. Similarly, in cases where streets do not have names or numbers properly displayed, such identification should be provided as one of the pre-census operations. Adequate identification provides the basis for the preparation of census control lists (see also "living quarters and household listing"); it is required in order to monitor and control the enumeration, and to identify living quarters for possible call-backs and post-enumeration evaluation surveys as well as for other post-censal inquiries that use the census as a sampling frame or other point of departure. Ideally, each building or other inhabited structure should be provided with a number, as should each set of living quarters within buildings or structures. In preparing a census control listing, it is the practice to identify further each household within the living quarters.

Living quarters that are not located in areas with a conventional pattern of streets, such as those in squatter areas or in some places not intended for habitation, may require special identification. Since it may not be possible to describe the location of these units in terms of a formal address, it may be necessary to describe them in terms of their proximity to natural or created landmarks of various kinds or in relation to buildings that are located in areas where a formal address is possible.

The various geographical designations that together define the location of living quarters are discussed below.

Address

Information that describes the place where the living quarters are to be found and distinguishes them from other living quarters in the same locality falls within this category. As a rule, the information includes the name or number of the street and the number of the living quarters; in the case of apartments, the building number and the apartment number are required.

E. Living quarters - type of (paras. 2.320-2.365)

(a) Definition of building

A building is any independent free-standing structure comprising one or more rooms or other spaces, covered by a roof and usually enclosed within external walls or dividing walls1 that extend from the foundations to the roof. However, in tropical areas, a building may consist of a roof with supports only, that is to say, without constructed walls; in some cases, a roofless structure consisting of a space enclosed by walls may be considered a "building" (see also "compound").

• (i) Separateness and independence

  The essential features of living quarters are separateness and independence. An enclosure may be considered separate if surrounded by walls, fences, and so forth, and covered by a roof so that a person or group of persons can isolate themselves from other persons in the community for the purposes of sleeping, preparing and taking their meals, and protecting themselves from the hazards of climate and environment. Such an enclosure may be considered independent when it has direct access from the street or from a public or communal staircase, passage, gallery or grounds, in other words, when the occupants can come in and go out of their living quarters without passing through anybody else's premises.

  Attached rooms having an independent entrance, or detached rooms for habitation that clearly have been built, say, or rebuilt or converted for use as part of living quarters should be counted as part of the living quarters. Thus, living quarters may comprise rooms or groups of rooms with independent entrances, or separate buildings.

• (ii) Permanence

  Living quarters may be permanent or semi-permanent buildings or structures, or parts of buildings, intended for habitation, or natural shelters not intended for habitation but actually used as a place of abode on the day or night established as the time reference of the census.

• (iii) Habitation

  Living quarters originally intended for habitation and used wholly for other purposes at the time of the census should normally be excluded from the census coverage, while shelters not intended for habitation but occupied at the time of the census should be included. In some circumstances, it may be convenient to make a separate count for national purposes of the sets of living quarters originally intended for habitation but used wholly for other purposes at the time of the census and vice versa. In such cases, specific instruction for the enumeration of these sets of living quarters must be supplied.

• (iv) Living quarters under construction, newly constructed, being demolished or awaiting demolition

  Instructions should be issued so that it is clearly understood at what stage of completion sets of living quarters should be included in the housing census. They may be included in the housing census as soon as construction has begun, at various stages of construction or when construction has been completed. Living quarters being demolished or awaiting demolition should normally be excluded. The system used should be consistent with that employed for the system of current housing statistics and should avoid double counting where construction statistics are used to bring the census data up to date.

  Special instructions will need to be issued concerning "core dwellings" in countries where these are provided within a preliminary phase of dwelling construction (for a discussion of core dwellings).

(b) Classification of living quarters

The living quarters defined above are either housing units or collective living quarters. Normally, the collection of information concerning housing units will be considered of first importance in a housing census, since it is in housing units that the bulk of the population permanently lives. Furthermore, housing units are intended for occupancy, or are occupied, by households, and it is with the provision of accomare mainly concerned. However, certain types of "collective living quarters" are also of significance with respect to the housing conditions of households; these include hotels, rooming houses and other lodging houses and camps occupied by households. Housing units should be classified so as to distinguish at least conventional dwellings from other types of housing units.

The classification outlined below and a system of three-digit codes have been designed to group in broad classes housing units and collective living quarters with similar structural characteristics. The distribution of occupants (population) among the various groups supplies valuable information about the housing accommodation available at the time of the census. The classification also affords a useful basis of stratification for sample surveys. The living quarters may be divided into the following categories:

• 1. Housing units
• 1.1 Conventional dwellings
• 1.2 Basic dwellings
• 1.3 Temporary housing units
• 1.4 Mobile housing units
• 1.5 Marginal housing units
  • 1.5.1 Improvised housing units
  • 1.5.2 Housing units in permanent buildings not intended for human habitation
  • 1.5.3 Other premises not intended for human habitation
• 2. Collective living quarters
• 2.1 Hotels, rooming houses and other lodging houses
• 2.1 Institutions
• 2.1 Camps
• 2.1 Other

Not all the categories in the above classification are of importance under all circumstances. For example, in some countries certain of the groups may not need to be considered separately, while in others it will be convenient to subdivide them. However, some of the categories are of special significance for assessing the housing situation and should be distinguished even where a simplified classification is employed. The distinction between conventional and marginal housing units is referred to especially.

(c) Definition of each type of living quarters

1. Housing units
A housing unit is a separate and independent place of abode intended for habitation by a single household,2 or one not intended for habitation but occupied as living quarters by a household at the time of the census. Thus it may be an occupied or vacant dwelling, an occupied mobile or improvised housing unit or any other place occupied as living quarters by a household at the time of the census. This category includes housing of various levels of permanency and acceptability and therefore requires further classification in order to provide for a meaningful assessment of housing conditions

It should be noted that housing units on the grounds or within the buildings housing an institution, camp, and so forth should be separately identified and counted as housing units. For example, if, in the grounds of a hospital, there is a separate and independent house intended for the habitation of the director and his or her family, the house should be counted as a housing unit. In the same way, self-contained apartments located in hotel buildings should be counted as housing units if they have direct access to the street or to a common space within the building.

1.1 Conventional dwellings
A conventional dwelling is a room or suite of rooms and its accessories in a permanent building or structurally separated part thereof which, by the way it has been built, rebuilt or converted, is intended for habitation by one household and is not, at the time of the census, used wholly for other purposes. It should have a separate access to a street (direct or via a garden or grounds) or to a common space within the building (staircase, passage, gallery and so on). Examples of dwellings are houses, flats, suites of rooms, apartments and so forth.

A permanent building is understood to be a structure that may be expected to maintain its stability for 15 years or more, depending on the way countries define durability.

It may be noted that the terms dwelling, dwelling unit, dwelling house, residential dwelling unit, family dwelling, house, logement, vivienda, unidad de vivienda and so forth have been used indiscriminately to refer to living quarters of any type. The referent of the term "dwelling" is here limited to a housing unit located in a permanent building and designed for occupancy by one household. Although a conventional dwelling is a housing unit intended - that is to say, constructed or converted - for habitation by one household, it may, at the time of the census, be vacant or occupied by one or more households. Therefore, the essential elements of a conventional dwelling are:
A room or suit of rooms
Located in a permanent building
Separate access to a street or to a common space
Intended to be occupied by one household
Kitchen or other space for cooking within dwelling
Fixed bath or shower within dwelling
Toilet within dwelling
Piped water within dwelling

1.2 Basic dwellings
A basic dwelling is a housing unit that has some but not all of the essential facilities of a conventional dwelling. It is a permanent structure or a part of a permanent structure, hence it may be a room or a suite of rooms in a permanent building but it is without some of the conventional dwelling facilities such as kitchen, fixed bath or shower, piped water or toilet. In a number of countries or areas, a certain proportion of the housing inventory comprises such housing units which possess some but not all the characteristics of conventional dwellings.

With increased urbanization, the need for building lowcost housing units within the city limit has been developed. This housing most frequently consists of buildings containing a number of separate rooms whose occupants share some or all facilities (bathing, toilet or cooking facilities). Those units do not meet all the criteria of a conventional dwelling, especially from the point of view of maintaining health standards and privacy. Such a unit is known as a casa de palomar in Latin America.

Therefore, basic dwellings are more or less conventional from the point of view of permanency of structure but lack some of the housing facilities identified as essential (the four types being cooking facilities, bathing facilities, piped water and toilet).

1.3 Temporary housing unit
The term "temporary housing unit" refers to a structure that, by the way it has been built, is not expected to maintain its durability for as long a period of time as, but has some of the facilities of, a conventional dwelling. As discussed above, durability needs to be specifically defined on the basis of national standards and practices. The number of these units in some countries and areas may be substantial.

For example, in some countries "core" or "nuclear" dwellings around which a dwelling will eventually be constructed are provided as part of the housing programmes. In others, a significant proportion of the housing inventory is composed of dwellings that are constructed of locally available raw materials and may be less durable than conventional or basic dwellings.

Core dwellings
Many countries with insufficient resources to meet their housing needs have attempted to alleviate the housing conditions of the population living in squatter areas by providing core or nuclear dwellings. Under these programmes, the households move their improvised shacks from the squatter area to a new location, the idea being that gradually, and generally with government assistance of one kind or another, the households with core or nuclear dwellings will keep adding to the nucleus until they can abandon their shacks entirely.

A core dwelling is sometimes only a sanitary unit containing bathing and toilet facilities, to which may be added, in subsequent phases, the other elements that will finally make up the completed dwelling. Such units do not fall within the definition of a conventional or basic dwelling. However, although the household obviously continues to occupy its original shelter (which would probably be classified as an "improvised housing unit"), its housing situation is a vast improvement over that of households remaining in the squatter areas and the provision of the cores is a significant step towards the alleviation of housing shortages.

Semi-permanent dwellings
In still other countries and areas, the population has developed, over time, a traditional and typical type of housing unit that does not have all the characteristics of conventional or basic dwellings but is considered somewhat suitable from the point of view of climate and tradition. This is especially the case in many tropical and subtropical rural areas where housing units have been constructed or built with locally available raw materials such as bamboo, palm, straw or any similar materials. Such units often have mud walls, thatched roofs and so forth, and may be expected to last only for a limited time (from a few months to 10 years), although occasionally they may last for longer periods. This category is intended to cover housing units that are typical and traditional in many tropical rural areas. Such units may be known, for example, as cabins, ranchos or bohíos (Latin America), barastis (Bahrain), or barong barong (the Philippines).

1.4 Mobile housing units
A mobile housing unit is any type of living accommodation that has been produced to be transported (such as a tent) or is a moving unit (such as a ship, boat, barge, vessel, railroad car, caravan, trailer, yacht and so on) occupied as living quarters at the time of the census. Trailers and tents used as permanent living quarters are of special interest.

Although mobile housing units are significantly different from other housing units in that they can be readily moved or transported, mobility in itself is not necessarily a measure of quality. For the assessment of housing conditions in countries with a substantial number of mobile units, it may be useful to classify them further, as tents, wagons, boats, trailers, and so forth.

1.5 Marginal housing units
The term “marginal housing unit” refers to those units that do not have many of the features of a conventional dwelling and are generally characterized as unfit for human habitation, but that are used for that purpose at the time of the census. Therefore, it is neither a permanent structure nor one equipped with any of the essential facilities. Depending on national circumstances, countries should develop detailed instructions to distinguish between marginal and temporary housing units.

Marginal housing units comprise three sub-groups, namely, "improvised housing units", "housing units in permanent buildings not intended for human habitation" and "other premises not intended for human habitation". These units are characterized by the fact that they are either makeshift shelters constructed of waste materials and generally considered unfit for habitation (squatters' huts, for example) or places that are not intended for human habitation although in use for that purpose at the time of the census (barns, warehouses, natural shelters and so on). Under almost all circumstances, such places of abode represent unacceptable housing and they may be usefully grouped together in order to analyse the housing conditions of the population and to estimate housing needs. Each sub-group is defined below.

1.5.1 Improvised housing units
An improvised housing unit is an independent, makeshift shelter or structure, built of waste materials and without a predetermined plan for the purpose of habitation by one household, which is being used as living quarters at the time of the census. Included in this category are squatters' huts, poblaciones callampas (Chile), hongos (Peru), favelas (Brazil), sarifas (Iraq), jhuggis (India and Pakistan), gubuks (Indonesia), gecekondula (Turkey) and any similar premises arranged and used as living quarters, though they may not comply with generally accepted standards for habitation, and not having many of the characteristics of conventional dwellings. This type of housing unit is usually found in urban and suburban areas, particularly at the peripheries of the principal cities.

1.5.2 Housing units in permanent buildings not intended for human habitation
Included in this category are housing units (in permanent buildings) that have not been built, constructed, converted or arranged for human habitation but that are actually in use as living quarters at the time of the census. These include housing units in stables, barns, mills, garages, warehouses, offices, booths and so forth.

This category also may cover units and their occupants in buildings initially built for human habitation, but later abandoned with all services cut because of deterioration. These dilapidated buildings can be found, especially in large cities, still standing, although marked for demolition. They should be included in this category if inhabited.

Premises that have been converted for human habitation, although not initially designed or constructed for this purpose, should not be included in this category.

1.5.3 Other premises not intended for human habitation
This category refers to living quarters that are not intended for human habitation or located in permanent buildings but that are nevertheless being used as living quarters at the time of the census. Caves and other natural shelters fall within this category.

2. Collective living quarters
Collective living quarters include structurally separate and independent places of abode intended for habitation by common facilities, such as cooking and toilet installations, baths, lounge rooms or dormitories, which are shared by the occupants. As indicated above, they may be further classified into hotels, rooming houses and other lodging houses, institutions and camps.

The criteria established for the identification of collective living quarters are not always easy to apply and it is sometimes difficult for an enumerator to decide whether living quarters should be classified as a housing unit or not. This is particularly true in the case of a building occupied by a number of households. Enumerators should be given clear instructions as to when the premises occupied by a group of people living together are to be considered a housing unit and when collective living quarters.

2.1 Hotels, rooming houses and other lodging houses
This group comprises permanent structures that provide lodging on a fee basis and in which the number of borders or lodgers exceed five. Hotels, motels, inns, boarding houses, pensions, lodging houses and so forth fall within this category.

2.2 Institutions
This group covers any set of premises in a permanent structure or structures designed to house (usually large) groups of persons who are bound by either a common public objective or a common personal interest. Such sets of living quarters usually have certain common facilities shared by the occupants (baths, lounges, dormitories and so forth). Hospitals, military barracks, boarding schools, convents, prisons and so forth fall within this category.

2.3 Camps
Camps are sets of premises originally intended for the temporary accommodation of persons with common activities or interests. Included in this category are military camps, refugee camps and camps established for the housing of workers in mining, agriculture, public works or other types of enterprises.

F. Occupancy status (paras. 2.366-2.369)

Information should be obtained for each conventional dwelling and each basic dwelling to show whether the dwelling is occupied or vacant at the time of the census. For vacant units intended for year-round occupancy, the type of vacancy (for rent, for sale, and so forth) should be reported. Occupancy status applies only to conventional and basic dwellings, since all other types of living quarters are required by definition to be occupied in order to fall within the scope of the census.

The enumeration of vacant units is likely to pose difficult problems, but at least a total count should be made for purposes of controlling the enumeration and for the reasons stated under the uses of tabulation H8 (see annex II). The type of vacancy is frequently indicated by "for sale" or "for rent" signs posted on the dwelling. Although it may not be feasible to investigate all of the topics included in the census for vacant units, as much information as possible should be collected, including information on whether the living quarters are vacant seasonally or nonseasonally.

Vacant units intended for seasonal occupancy may represent a substantial proportion of the housing inventory in resort areas and in areas where large numbers of seasonal workers are employed. The separate identification of such a category may be necessary for the correct interpretation of the overall vacancy rate as well as for an evaluation of the housing situation in the area concerned. Vacant units may be further distinguished according to the type of occupancy for which they are intended, for example, as holiday home, seasonal workers' quarters and so forth.

Whether living quarters whose occupants are temporarily absent or temporarily present should be recorded as occupied or vacant will need to be considered in relation to whether a de jure or de facto population census is being carried out. In either case, it would seem useful to distinguish as far as possible living quarters that are used as a second residence. This is particularly important if the second residence has markedly different characteristics from the primary residence, as is the case, for example, when agricultural households move during certain seasons of the year from their permanent living quarters in a village to rudimentary structures located on agricultural holdings. The recommended classification for conventional and basic dwellings is as follows:

• 1. Occupied
• 2. Vacant
• 2.1 Seasonally vacant
• 2.2 Non-seasonally vacant
• 2.2.1 For rent
• 2.2.2 For sale
• 2.2.3 For demolition
• 2.2.4 Other

G. Ownership - type of (paras. 2.370-2.374)

This topic refers to the type of ownership of the living quarters themselves and not of that of the land on which the living quarters stand. Type of ownership should not be confused with tenure, which is discussed below. Information should be obtained to show:

(a) Whether the living quarters are owned by the public sector (central government, local government, public corporations);

(b) Whether the living quarters are privately owned (by households, private corporations, cooperatives, housing associations and so on). The question is sometimes expanded to show whether the living quarters are fully paid for, being purchased in instalments or mortgaged. The classification of living quarters by type of ownership is as follows:

• 1. Owner-occupied
• 2. Non owner-occupied
• 2.1 Publicly owned
• 2.2 Privately owned
• 2.3 Other

Living quarters are defined as owner-occupied if used wholly or partly for own occupation by the owner. Special instructions should be issued regarding living quarters being purchased in instalments or mortgaged according to national legal systems and practice. Instructions should also cover other arrangements, such as living quarters in cooperatives, housing associations and so forth.

The information on ownership may be classified, as a minimum, into two main groups, namely public ownership and private ownership. Depending upon the prevalence of various types of ownership and their significance with respect to housing conditions and the formulation of housing programmes, it may be useful to introduce some of the sub-groups shown. The categories used should be consistent with those employed in the system of national accounts of the country concerned and in accordance with the recommendations contained in the System of National Accounts, 1993.

H. Rooms - number of (paras. 2.375-2.377)

A room is defined as a space in a housing unit or other living quarters enclosed by walls reaching from the floor to the ceiling or roof covering, or to a height of at least two metres, of an area large enough to hold a bed for an adult, that is, at least four square metres. The total number of types of rooms therefore includes bedrooms, dining rooms, living rooms, studies, habitable attics, servants' rooms, kitchens, rooms used for professional or business purposes, and other separate spaces used or intended for dwelling purposes, so long as they meet the criteria concerning walls and floor space. Passageways, verandas, lobbies, bathrooms and toilet rooms should not be counted as rooms, even if they meet the criteria. Separate information may be collected for national purposes on spaces of less than four square metres that conform in other respects to the definition of “room” if it is considered that their number warrants such a procedure.

Rooms used exclusively for business or professional purposes should be counted separately, as it is desirable to include them when calculating the number of rooms in a dwelling but to exclude them when calculating the number of persons per room. This procedure allows density levels to be studied according to the number of rooms available for living purposes in relation to the number of occupants. In any event, each country should indicate the procedure that has been followed.

It is recommended above that kitchens be included in the count of rooms provided they meet the criteria concerning walls and floor space. Kitchens or kitchenettes that have an area smaller than four square metres or that have other characteristics that disqualify them should be excluded. For national purposes, countries may wish to identify and count kitchens within a separate group that may be analysed with respect to size and utilization, and to consider separately those used exclusively for cooking.

I. Floor space - useful and/or living (paras. 2.378-2.380)

This topic refers to the useful floor space in housing units, that is to say, the floor space measured inside the outer walls of housing units, excluding non-habitable cellars and attics. In multiple-dwelling buildings, all common spaces should be excluded. The approach for housing units and collective living quarters should differ.

For collective living quarters, it would be more useful to collect information on the useful floor space per occupant of the set of collective living quarters. Data should be derived by dividing the total useful floor space by the number of occupants who are living in the space.

J. Water supply system (paras. 2.381-2.383)

The basic information to be obtained in the census is whether housing units have or do not have a piped water installation, in other words, whether or not water is provided to the living quarters by pipes from a community-wide system or an individual installation, such as a pressure tank, pump and so forth. The unit of enumeration for this topic is a housing unit. It is also necessary to indicate whether the unit has a tap inside or, if not, whether it is within a certain distance from the door. The recommended distance is 200 metres, assuming that access to piped water within that distance allows occupants of the housing unit to provide water for household needs without being subjected to extreme efforts. Beside the location of a tap, the source of water available is also of special interest. Therefore, the recommended classification of housing unit by water supply system is as follows:

• 1. Piped water inside the unit
• 1.1 From the community scheme
• 1.2 From a private source
• 2. Piped water outside the unit but within 200 metres
• 2.1 From the community scheme
• 2.1.1 For exclusive use
• 2.1.2 Shared
• 2.2 From a private source
• 2.2.1 For exclusive use
• 2.2.2 Shared
• 3. No piped water available (including piped water from a source beyond a distance of 200 metres from the living quarters)

A community scheme is one that is subject to inspection and control by public authorities. Such schemes are generally operated by a public body but in some cases they are generated by a cooperative or private enterprise.

For collective living quarters, it may be useful to collect information on the availability of piped water for the use of occupants. Such living quarters are usually equipped with multi-facilities for the use of large groups, and information on the water supply system in relation to the number of occupants would be significant in respect of analysing housing conditions. The water supply system in collective living quarters constitutes an additional topic.

The most significant information from a health point of view is whether the living quarters have piped water within the premises. However, a category may be added to distinguish cases where the piped water supply is not within the living quarters but rather within the building in which the living quarters are situated. It may also be useful to collect information that would show whether the water supply is for the sole use of the occupants of the living quarters being enumerated or whether it is for the use of the occupants of several sets of living quarters, as indicated in the above classification at the threedigit level. Additional information may be sought on the availability of hot as well as cold water and on the kind of equipment used for heating water.

K. Toilet and sewerage facilities (paras. 2.384-2.389)

A toilet may be defined as an installation for the disposal of human excreta. A flush toilet is an installation provided with piped water that permits humans to discharge their wastes and from which the wastes are flushed by water. The unit of enumeration for this topic is a housing unit.

For living quarters reported as having a toilet, additional information may be sought to determine whether the toilet is used exclusively by the occupants of the living quarters being enumerated or whether it is shared with the occupants of other living quarters. For living quarters reported as having no toilet, it would be useful to know whether the occupants have the use of a communal facility and the type of facility, whether they have the use of the toilet of other living quarters and the type, or whether there is no toilet of any kind available for the use of the occupants.

Some countries have found it useful to expand the classification for non-flush toilets so as to distinguish certain types that are widely used and indicate a certain level of sanitation. The recommended classification of housing unit by toilet facilities is as follows:

• 1. With toilet within housing unit
• 1.1 Flush toilet
• 1.2 Non-flush toilet
• 2. With toilet outside housing unit
• 2.1 Flush toilet
• 2.1.1 For exclusive use
• 2.1.2 Shared
• 2.2 Non-flush toilet
• 2.2.1 For exclusive use
• 2.2.2 Shared
• 3. No toilet available

L. Bathing facilities (paras. 2.390-2.391)

Information should be obtained on whether or not there is a fixed bath or shower installation within the premises of each set of living quarters. The unit of enumeration for this topic is a housing unit. Additional information may be collected to show whether or not the facilities are for the exclusive use of the occupants of the living quarters and where there is a supply of hot water for bathing purposes or cold water only. In some areas of the world the distinction proposed above may not be the most appropriate for national needs. It may be important, for example, to distinguish in terms of availability among a separate room for bathing in the living quarters, a separate room for bathing in the building, an open cubicle for bathing in the building and a public bathhouse. The recommended classification of housing units by availability and type of bathing facilities is as follows:

• 1. With fixed bath or shower within housing unit
• 2. Without fixed bath or shower within housing unit
• 2.1 Fixed bath or shower available outside housing unit
• 2.1.1 For exclusive use
• 2.1.2 Shared
• 2.2 No fixed bath or shower available

For housing units occupied by more than a certain number of households (more than two, for example) and for collective living quarters, particularly those of the multi-household and hotel/boarding-house type, it may be useful to gather information on the number of fixed baths or showers available to the occupants. Living quarters of this type are usually equipped with multi-facilities for the use of large groups, and information on the number of fixed baths or showers in relation to the number of occupants would be significant in terms of analysing housing conditions. The number of fixed baths or showers in collective living quarters would represent an additional topic.

M. Cooking facilities (paras. 2.392-2.397)

Information should be obtained on whether the living quarters have a kitchen, whether some other space is set aside for cooking such as a kitchenette, or whether there is no special place set aside for cooking. The unit of enumeration for this topic is a housing unit.

A kitchen is defined as a space that conforms in all respects to the criteria for a room, as defined above, and is equipped for the preparation of the principal meals of the day and intended primarily for that purpose.

N. Lightening - type of and/or electricity (paras. 2.398-2.399)

Information should be collected on the type of lighting in the living quarters, such as electricity, gas, oil lamp and so forth. If the lighting is by electricity, some countries may wish to collect information showing whether the electricity comes from a community supply, generating plant or some other source (industrial plant, mine and so on). In addition to the type of lighting, countries should assess the information on the availability of electricity for purposes other than lighting (such as cooking, heating water, heating the premises and so forth). If housing conditions in the country allow this information to be derived from the type of lighting, there would be no need for additional inquiry.

For collective living quarters, it may be useful to collect information on availability of electricity to the occupants. Such living quarters are usually equipped with multi-facilities for the use of large groups, and information on electricity would be significant in terms of analysing housing conditions. The availability of electricity in collective living quarters is defined as an additional topic.

O. Solid waste disposal - type of (paras. 2.400-2.401)

Securing sustainable development and, in this context, the treatment of solid waste prompted the incorporation of this topic in a number of national housing censuses. It does not seem to be debatable that household surveys represent a more suitable way of collecting data on solid waste disposal; however, in order to establish reliable and sound information that could be used as a benchmark for future data collection, countries should consider incorporating this topic in the forthcoming round of population and housing censuses (the 2000 round), as a "temporary" basic topic.

This topic refers to the collection and disposal of solid waste generated by occupants of the housing unit. The unit of enumeration is a housing unit. The classification of housing units by type of solid waste disposal is according to the following guidelines:

• 1 Solid waste collected on a regular basis by authorized collectors
• 2 Solid waste collected on an irregular basis by authorized collectors
• 3 Solid waste collected by self-appointed collectors
• 4 Occupants dispose of solid waste in a local dump supervised by authorities
• 5 Occupants dispose of solid waste in a local dump not supervised by authorities
• 6 Other arrangements (including incineration of solid waste by occupants)

P. Occupancy by one or more households (paras. 2.402-2.406)

For the purpose of a housing census, each household must be identified separately. With respect to housing programmes, the use of the separate concepts of household and living quarters in carrying out housing censuses permits the identification of the persons or groups of persons in need of their own dwellings. If the household is defined as a group of households in the living quarters and the number of sets of occupied living quarters will always be equal and there will be no apparent housing need as reflected by doubled-up households requiring separate sets of living quarters. If living quarters are defined as the space occupied by a household, the number of households in living quarters will again be equal to the number of sets of living quarters, with the added disadvantage that there will be no record of the number of structurally separate living quarters.

Q. Occupants - number of (para. 2.407)

Each person usually resident in a housing unit or set of collective living quarters should be counted as an occupant. Therefore, the units of enumeration for this topic are living quarters. However, since housing censuses are usually carried out simultaneously with population censuses, the applicability of this definition depends upon whether the information collected and recorded for each person in the population census indicates where he or she was on the day of the census or whether it refers to the usual residence. Care should be exercised in distinguishing persons occupying mobile units, such as boats, caravans and trailers, as living quarters from persons using these units as a means of transportation.

R. Demographic and economic characteristics of the head of the household (paras. 2.408-2.409)

2.409. In some cases, the characteristics of the person identified as the head of the household might not be of significance in connection with the housing conditions of the household. To provide a basis for valid assumptions concerning this relationship, the circumstances likely to affect it should be carefully considered and provided for in carrying out census tests and in analysing the results of those tests. Post-enumeration evaluation surveys will provide a further opportunity to examine the relationship between the characteristics (see directly below) of those identified as heads of the household and the housing conditions of the household in question.

• (a) Age: for the definition of age
• (b) Sex: for the definition of sex
• (c) Activity status: for the definition of activity status
• (d) Occupation: for the definition of occupation

S. Tenure (paras. 2.410-2.412)

Tenure refers to the arrangements under which the household occupies all or part of a housing unit. The unit of enumeration is a household occupying a housing unit. The classification of households by tenure is as follows:

• 1. Member of household owns a housing unit
• 2. Member of household rents all or a part of housing unit
• 2.1 Member of household rents all or a part of housing unit as a main tenant
• 2.2 Member of household rents a part of housing unit as a subtenant
• 3. Other arrangement

Particular attention needs to be given to persons who occupy premises free of cash rent, with or without the permission of the owner, especially where this is prevalent.

The question of tenure needs to be clearly distinguished in the questionnaire as one to be asked of all households; otherwise there is a danger that it may be omitted in cases where more than one household occupies a single housing unit. Tenure information collected for living quarters shows very clearly the distinction between rented units and units that are owner-occupied, but it fails to distinguish the various forms of subtenancy that exist in many areas, information regarding which could be obtained from a question directed at households, nor does it allow for an investigation of the relationship between tenure and socio-economic characteristics of heads of the household. Under some circumstances, it may be useful to indicate separately households that, although not subtenants in the sense that they rent from another occupant who is a main tenant or owner-occupant, rent part of a housing unit from a landlord who lives elsewhere. These households and subtenant households may be of special significance in formulating housing programmes. On the contrary, in countries where subtenancy is not usual, information on subtenants may not be collected in the census or, if collected, may be tabulated only for selected areas.

T. Rental and owner -occupant housing costs (paras. 2.413-2.415)

Rent is the amount paid periodically (weekly, monthly, and so forth) for the space occupied by a household. Information may be obtained on the basis of a scale of rents rather than on that of the exact amount paid. The data may be considered in relation either to household characteristics or to the characteristics of the living quarters. In the latter case, where more than one household occupies a single set of living quarters, the rents paid by all the households will need to be summed in order to obtain the total rent for the living quarters. In the case of living quarters that are partly rented and partly owneroccupied, it may be necessary to impute the rent for the owneroccupied portion.

Provision must be made for indicating whether the living quarters covered by the rent are furnished or unfurnished and whether utilities such as gas, electricity, heat, water and so forth are included. Provision also needs to be made for recording households that occupy their premises rent-free or pay only part of the economic rent. In countries where rent for the living quarters is paid separately from rent for the land upon which they stand, separate information may need to be collected reflecting the amount of ground rent paid.

Footnotes

1 The term "dividing walls" refers to the walls of adjoining buildings that have been so constructed as to be contiguous, for example, the dividing walls of "row" houses.

2 Although intended for habitation by one household, a housing unit 91 may, at the time of the census, be occupied by one or more households or by a part of a household.