This section presents data on the construction industry and on various indicators of its activity and costs; on housing units and their characteristics and occupants; and on the characteristics and vacancy rates for commercial buildings. This edition contains data from the 2002 American Housing Survey in metropolitan areas.

The principal source of these data is the U.S. Census Bureau, which issues a variety of current publications, as well as data from the decennial census. Current construction statistics compiled by the Census Bureau appear in its New Residential Construction and New Residential Sales press releases and Web sites <http://www.census.gov/const/www/>.Statistics on expenditures by owners of residential properties are issued quarterly and annually in Expenditures for Residential Upkeep and Improvements. Value of New Construction Put in Place presentsdata on all types of construction and includes monthly composite cost indexes. Reports of the censuses of construction industries (see below) are also issued on various topics.

Other Census Bureau publications include the Current Housing Reports series, which comprises the quarterly Housing Vacancies, the quarterly Market Absorption of Apartments, the biennial AmericanHousing Survey (formerly Annual HousingSurvey), and reports of the censuses of housing and of construction industries. Construction Review, published quarterly by the International Trade Administration, U.S. Department of Commerce, contains many of the census series and other construction statistics series from the federal government and private agencies.

Other sources include the monthly DodgeConstruction Potentials of F. W. Dodge Division, McGraw-Hill Information Systems Company, New York, NY, which presents national and state data on construction contracts; the National Association of Home Builders with state-level data on housing starts; the NATIONAL ASSOCIATION OF REALTORS®, which presents data on existing home sales; the Society of Industrial and Office Realtors and Oncor International on commercial office and industrial space; the Bureau of Economic Analysis, which presents data on residential capital and gross housing product; and the U.S. Energy Information Administration, which provides data on commercial buildings through its periodic sample surveys.

Censuses and surveys-Censuses of the construction industry were first conducted by the Census Bureau for 1929, 1935, and 1939; beginning in 1967, a census has been taken every 5 years (through 1997, for years ending in ‘‘2’’ and ‘‘7’’). The latest complete reports are for 1997. The 1997 census results are part of the 1997 Economic Census. See Table 932. See also text, Section 15, Business Enterprise.

The construction sector of the economic census, covers all employer establishments primarily engaged in (1) building construction by general contractors or operative builders; (2) heavy (nonbuilding) construction by general contractors; and (3) construction by special trade contractors. The 1997 census was conducted in accordance with the 1997 North American Industry Classification System (NAICS); the 1992 census was conducted in accordance with the 1987 StandardIndustrial Classification (SIC). This sector now includes construction management and land subdividers and developers, not included previously. See text, Section 15, Business Enterprise, for general information on the SIC and NAICS.

From 1850 through 1930, the Census Bureau collected some housing data as part of its censuses of population and agriculture. Beginning in 1940, separate censuses of housing have been taken at 10-year intervals. For the 1970 and 1980 censuses, data on year-round housing units were collected and issued on occupancy and structural characteristics, plumbing facilities, value, and rent; for 1990 such characteristics were presented for all housing units.

The American Housing Survey (CurrentHousing Reports Series H-150 and H-170), which began in 1973, provided an annual and ongoing series of data on selected housing and demographic characteristics until 1983. In 1984, the name of the survey was changed from the Annual Housing Survey. Currently, national data are collected every other year, and data for selected metropolitan areas are collected on a rotating basis. All samples represent a cross section of the housing stock in their respective areas. Estimates are subject to both sampling and nonsampling errors; caution should therefore be used in making comparisons between years.

Data on residential mortgages were collected continuously from 1890 to 1970, except 1930, as part of the decennial census by the Census Bureau. Since 1973, mortgage status data, limited to single family homes on less than 10 acres with no business on the property, have been presented in the American Housing Survey. Data on mortgage activity are covered in Section 25, Banking and Finance.

Housing units-In general, a housing unit is a house, an apartment, a group of rooms or a single room occupied or intended for occupancy as separate living quarters; that is, the occupants live separately from any other individual in the building, and there is direct access from the outside or through a common hall. Transient accommodations, barracks for workers, and institutional-type quarters are not counted as housing units.

Statistical reliability-For a discussion of statistical collection and estimation, sampling procedures, and measures of statistical reliability applicable to Census Bureau data, see Appendix III.