A housing unit is "owner occupied" if the owner or co-owner lives in the unit even if the unit is mortgaged or not fully paid for. The owner or co-owner must live in the unit but need not be the person listed in column 1 of the 1980 census questionnaire.

All occupied housing units which are not owner occupied, regardless of whether cash rent is paid by a member of the household. ("No cash rent" units, a subcategory of renter occupied, are separately identified in rent tabulations. Such units are generally one provided free by friends or relatives, or in exchange for the services of, for example, a caretaker, minister, tenant farmer, or sharecropoer.)

Tenure has been collected since 1890. In 1970, the question on tenure also included a category for condominium and cooperative ownership. In 1980, condominiums are identified in a separate question.

See also: "Condominium Status;" "Owner Costs, Selected Monthly;" "Rent, Contract;" "Rent, Gross;" "Value".

A housing unit occupied as the usual place of residence of a person or group of Persons living in it at the time of enumeration, or by occupants only temporarily absent such as on vacation. A household consists of all the persons who occupy a housing unit as their usual place of residence. If all the persons staying in the unit at the time of enumeration have their usual place of residence elsewhere, the unit is classified as vacant. Complete count figures on households and occupied housing units should match--although sample estimates of households and occupied housing units may differ because of weighting.

A housing unit with no one living in it at the time of enumeration, unless its occupants are only temporarily absent. If, at the time of enumeration, the unit is temporarily occupied solely by persons who have a usual residence elsewhere, it is also classified as vacant.

New units not yet occupied are classified as vacant housing units if construction has reached a point where all exterior windows and doors are installed and final usable floors are in place.

Vacant units are excluded if open to the elements; that is, if the roof, walls, windows, or doors no longer protect the interior from the elements, or if there is positive evidence (such as a sign on the house or in the block) that the unit is to be demolished or is condemned. Also excluded are quarters being used entirely for nonresidential purposes, such as a store or an office, or quarters used for the storage of business supplies or inventory, machinery, or agricultural products.

Similar data have been collected since 1940.

See also: "Vacancy Status".

Year-built data are particularly susceptible to response errors and nonreporting since respondents must rely on their memory or estimates of persons, who have lived in the neighborhood a long time, etc. A 1970 census evaluation study found greater inconsistencies between the census and reinterviews among earlier year-built categories than among categories for more recent periods.

Similar data have been collected since 1940. The categories in 1970 were: 1939 or earlier, 1940 to 1949, 1950 to 1959, 1960 to 1964, 1965 to 1968, and 1969 to 1970.