Vacant units held off the rental or sale market for other reasons (and for year-round use and not dilapidated) amounted to 1.6 percent of the total inventory. Some were held for occasional use by their owners or were in litigation; others were reserved for servants, caretakers, janitors, and the like, or were held off the market for personal reasons of the owner; and still others were not offered for rent or sale because they were in places where there was little demand for housing, especially areas where the population in recent years increased very little or has declined. The bulk of the units "held off the market" were in rural areas. The regional pattern of such vacancies follows closely the pattern of vacancies offered for rent or sale. The West had the largest proportion of vacancies held. off the market (2.6 percent), and the Northeast had the smallest percent).

(0.7

for rent or sale. Vacancies in the dilapidated group are among the units most likely to drop out of the housing inventory. Vacant units which are unfit for human habitation or deteriorated to the extent that they are no longer considered living quarters are not included in the statistics for this report.

The three groups of year-round vacancies (rented or sold, held off market, and dilapidated), added to the available vacancies, bring the total year-round rate to 5.5 percent.

Seasonal units

DEFINITIONS AND EXPLANATIONS

Except for the few instances noted below, the concepts and definitions used in the 1955 quarterly survey are identical with those used in the 1950 Census. However, the content of the 1955 survey differed slightly from the 1950 Census. In 1955, but not in 1950, information was collected on the number of bedrooms, duration of vacancy, and inclusion of utilities in rent. On the other hand, the 1950 Census included questions on plumbing facilities and year built. In both years, information was obtained on number of rooms in the unit, number of dwelling units in the structure, condition, status, monthly rent, and sale price.

Urban-rural residence.--Urban housing comprises all dwelling units in (a) places of 2,500 inhabitants or more incorporated as cities, boroughs, and villages, (b) incorporated towns of 2,500 inhabitants or more except in New England, New York, and Wisconsin, where "towns" are simply minor civil divisions of counties, (c) the densely settled urban fringe around cities of 50,000 inhabitants or more, including both incorporated and unincorporated areas, and (d) unincorporated places of 2,500 inhabitants or more outside any urban fringe. The remaining dwelling units are classified as rural.

The urban classification thus includes, in addition to dwelling units in urban places, the housing in closely settled areas in the vicinity of large cities. These areas, known as the "urban fringe," were established to conform as nearly as possible to the actual boundaries of thickly settled territory, usually characterized by a closely spaced street pattern. Urban fringe areas were set up for each city of 50,000 inhabitants or more just prior to the 1950 Census. Thus, some concentrations of new housing just outside city limits may be classified as rural.

The definition for urban housing, given above, is that used for the 1950 Census. The identification and boundaries of urban places and urban fringes established for the 1950 Census were not brought up to date for the 1955 statistics so that the designation of urban housing is the same for both years.

The rural classification comprises a variety of residences, such as isolated homes in the open country and dwelling units in villages and hamlets of fewer than 2,500 inhabitants.

Nonfarm residence.--Nonfarm dwelling units are defined to include all units not on farms. For occupied units, the farm-nonfarm classification is based on the respondent's reply to the question, "Is this house on a farm?" Farm residence is, therefore,

Standard metropolitan areas.--Except in New England, a standard metropolitan area is a county or group of contiguous counties which contains at least one city of 50,000 inhabitants or more at the time of the 1950 Census. Counties contiguous to the one containing such a city are included in a standard metropolitan area if according to certain criteria they are essentially metropolitan in character and socially and economically integrated with the central city. In New England, towns and cities were the units used in defining standard metropolitan areas. Here a population density criterion was applied rather than the criteria relating to metropolitan character.

Statistics for "inside standard metropolitan areas" in table 2 are for all vacant dwelling units-urban and rural, farm and nonfarm--which are located within the counties and places comprising standard metropolitan areas.

For a list of all standard metropolitan areas, and their constituent counties (cities, towns), refer to the individual chapters (or bulletins) in the 1950 Census of Housing, Volume I, General Characteristics; or to the 1950 Census of Population, Volume I, Number of Inhabitants, or Volume II, Characteristics of the Population, Part 1, United States Summary.

The standard metropolitan areas were established at the time of the 1950 Census. Both the 1950 and 1955 statistics relate to these same (168) areas. A map identifying the standard metropolitan areas and their location is given on page 12 of this report.

Dwelling units.--In general, a dwelling unit is a group of rooms or a single room occupied or intended for occupancy as separate living quarters by a family or other group of persons living together or by a person living alone.

Ordinarily, a dwelling unit is a house, an apartment, or a flat. A dwelling unit may be located

A group of rooms, occupied or intended for occupancy as separate living quarters, is a dwelling unit if it has separate cooking equipment or separate entrance. A single room, occupied or intended for occupancy as separate living quarters, is a dwelling unit if it has separate cooking equipment or if it constitutes the only living quarters in the structure. Each apartment in a regular apartment house is a dwelling unit even though it may not have separate cooking equipment. Apartments in residential hotels are dwelling units if they have separate cooking equipment or consist of two or more rooms. Since it is customary in some localities for the intended occupants to furnish their own cooking equipment, vacant units were considered as having cooking equipment if they were currently equipped with or if the last occupants had such equipment.

Living quarters of the following types are not included in the dwelling unit inventory: Sleeping rooms in rooming houses; transient accommodations (tourist courts, hotels, etc., predominantly for transients); and barracks for workers (railroad, construction, etc.). Living quarters in institutions (for delinquent or dependent children, handicapped persons, the aged, prisoners, etc.), general hospitals, and military installations are likewise excluded from the dwelling unit inventory except for dwelling units in buildings containing only family quarters for staff members.

Nonresident dwelling units.--A nonresident dwelling unit is a unit which is occupied temporarily by persons who usually live elsewhere, provided the usual place of residence is held for the household and is not offered for rent or for sale. For example, a beach cottage occupied at the time of enumeration by a family which has a usual place of residence in the city is considered a nonresident unit. Their house in the city would be reported "occupied" and would be included in the count of occupied units since the occupants are only temporarily absent.

Nonresident units in the 1955 statistics are included with seasonal units or with year-round

vacant units as dilapidated, or not dilapidated but held off the market, as the case may be. In the 1950 reports, the nonresident units were shown as a separate category; for comparison with the 1955 results, however, these units were distributed among seasonal, dilapidated, and not dilapidated units held off the market.

Vacant dwelling units.--A dwelling unit (furnished or unfurnished) is vacant if no persons were living in it at the time of enumeration, except when its occupants were only temporarily absent. Dilapidated vacant dwelling units were included if they were intended for occupancy as living quarters; however, if the unit was unfit for use and beyond repair so that it was no longer considered living quarters, it was excluded from the inventory. New units not yet occupied were enumerated as vacant dwelling units if construction had proceeded to the point that all the exterior windows and doors were installed and final usable floors were in place; otherwise, potential units under construction were not included. Unoccupied units held off the market for various reasons and units recently rented or sold but not yet occupied are considered vacant.

Vacant sleeping rooms in lodginghouses, transient accommodations, barracks, and other quarters not defined as dwelling units are not included in the statistics in this report. (See section on "Dwelling units.")

Seasonal units.--Seasonal dwelling units are those intended for occupancy during only a portion of the year and are found primarily in resort areas. In farm areas, dwelling units used for only a portion of the year to house migratory workers employed during the crop season are classified as seasonal.

Seasonal units comprise unoccupied seasonal units and seasonal units temporarily occupied by nonresidents. Units in resort areas occupied by persons who considered the unit their usual place of residence or had no other place of residence are classified as occupied. (See also section on "Occupied dwelling units.")

Year-round vacant units.--Year-round units are those intended for year-round occupancy, even though they may not be in use the year round. In resort areas, a dwelling unit which is usually occupied on a year-round basis was considered a year-round unit. On the other hand, a dwelling unit located in the closely built-up area of a nonresort city was considered a "year-round" unit even though it may be occupied only part of the year. As indicated above, year-round units temporarily occupied by persons with usual residence elsewhere are included with year-round vacant units.

Condition of dwelling unit.--The structural condition of a dwelling unit is considered one of the measures of the quality of housing. me measu condition, the vacant dwelling units were classified as "not dilapidated" or "dilapidated."