– The sample estimate and an estimate of its standard error allow us to construct interval estimates with prescribed confidence that the interval includes the average result of all possible samples with the same size and design. To illustrate, if all possible samples were surveyed under essentially the same conditions, and estimates calculated from each sample, then:
Approximately 68 percent of the intervals from one standard error below the estimate to one standard error above the estimate would include the average value of all possible samples.
Approximately 90 percent of the intervals from 1.6 standard errors below the estimate to 1.6 standard errors above the estimate would include the average value of all possible samples.
Thus, for a particular sample, one can say with specified confidence that the average of all possible samples is included in the constructed interval.
– When a report is not received from a building permit office, missing housing unit data are either obtained by using permits listed for the Census Bureau's Survey of Construction (SOC) or are imputed. Data from the SOC are available for only about 900 permit offices. For places not in the SOC, imputations are used. Imputations are based on the assumption that the ratio of current month or year authorizations to the prior annual total should be the same for reporting and nonreporting places.
Data labeled as "Estimates with Imputation" include the imputed data as well as reported data from the respondent or from the SOC.
– Federal Information Processing Standard (FIPS) codes uniquely identify states, counties, and other related location entities. These are now more properly named the ANSI codes for the American National Standards Institute. For details, see the ANSI website: http://www.census.gov/geo/www/ansi/ansi.html
– Footnotes are available to explain changes in building permit coverage for individual municipalities. In most cases, these clarify the actual geographic coverage of a permit office, which is not always obvious from the place name.
– A housing unit, as defined for purposes of these data, is a house, an apartment, a group of rooms, or a single room intended for occupancy as separate living quarters. Separate living quarters are those in which the occupants live separately from any other individuals in the building and which have a direct access from the outside of the building or through a common hall.
In accordance with this definition, each apartment unit in an apartment building is counted as one housing unit. Housing units, as distinguished from "HUD-code" manufactured (mobile) homes, include conventional "site-built" units, prefabricated, panelized, sectional, and modular units.
Housing unit statistics also exclude group quarters (such as dormitories and rooming houses), transient accommodations (such as transient hotels, motels, and tourist courts), moved or relocated buildings, and housing units created in an existing residential or nonresidential structure.
Units in assisted living facilities are considered to be housing units, however, units in nursing homes are not considered to be housing units.
"HUD-code" Manufactured (mobile) Home
– A manufactured home is defined as a movable dwelling, 8 feet or more wide and 40 feet or more long, designed to be towed on its own chassis, with transportation gear integral to the unit when it leaves the factory, and without need of a permanent foundation. These homes are built in accordance with the U.S. Department of Housing and Urban Development (HUD) building code.
– The titles and definitions for Metropolitan Areas (MAs), which are made up of Metropolitan Core-Based Statistical Areas (CBSAs), conform to those defined by the Office of Management and Budget, Executive Office of the President, as of December 2003. More information on Metropolitan Areas can be found at http://www.census.gov/population/www/metroareas/metrodef.html.
– Residential buildings containing units built one on top of another and those built side-by-side which do not have a ground-to-roof wall and/or have common facilities (i.e., attic, basement, heating plant, plumbing, etc.)
– The category of statistics called "New Residential Construction" consists of data on the five phases of a residential construction project: (1) housing units authorized to be built by a building or zoning permit; (2) housing units authorized to be built, but not yet started; (3) housing units started; (4) housing units under construction; and (5) housing units completed.
New residential construction statistics exclude group quarters (such as dormitories and rooming houses), transient accommodations (such as transient hotels, motels, and tourist courts), "HUD-code" manufactured (mobile) homes, moved or relocated buildings, and housing units created in an existing residential or nonresidential structure.
In a new building combining residential and nonresidential floor areas, every effort is made to include the residential units in these statistics, even if the primary function of the entire building is for nonresidential purposes.
These statistics only include privately-owned buildings. Publicly-owned housing units are excluded from the statistics. Units in structures built by private developers with partial public subsidies or which are for sale upon completion to local public housing authorities under the HUD "Turnkey" program are all classified as private housing.
Not Seasonally Adjusted
– Data labeled "Not Seasonally Adjusted" refers to the fact that the data are not adjusted for seasonality using seasonal adjustment and not shown at an annual rate.
– A geographic area that issues building or zoning permits for the construction of residential structures. The area may be a single municipality or county or a combination of multiple municipalities.
– Structures not owned by any federal, state, or local government. Units in structures built by private developers with partial public subsidies or which are for sale upon completion to local public housing authorities under the HUD "Turnkey" program are all classified as private housing.
– Public housing is a residential building owned by a federal, state or local agency.
Units in structures built by private developers with partial public subsidies or which are for sale upon completion to local public housing authorities under the HUD "Turnkey" program are all classified as private housing.
– The estimated standard error expressed as a percent of the estimated total or proportion, that is, the estimated standard error times 100 divided by the estimate. This is also called coefficient of variation (CV).
– A residential building is a building consisting primarily of housing units. In a new building combining residential and nonresidential floor areas, every effort is made to include the residential units in these statistics, even if the primary function of the entire building is for nonresidential purposes.
– Data labeled as "Reported Data" include the data reported from the respondent or from the Census Bureau's Survey of Construction (SOC) but exclude imputed data.
– Seasonal adjustment is the process of estimating and removing seasonal effects from a time series to better reveal certain non-seasonal features such as underlying trends and business cycles. Seasonal adjustment procedures estimate effects that occur in the same calendar month with similar magnitude and direction from year to year. In series whose seasonal effects come primarily from weather, the seasonal factors are estimates of average weather effects for each month. Seasonal adjustment does not account for abnormal weather conditions or for year-to-year changes in weather. Seasonal factors are estimates based on present and past experience. Future data may show a different pattern.
Most of the seasonally adjusted series are shown as seasonally adjusted annual rates (SAAR). The seasonally adjusted annual rate is the seasonally adjusted monthly value multiplied by 12. The benefit of the annual rate is that not only can one monthly estimate be compared with another; monthly data can also be compared with an annual total. The seasonally adjusted annual rate is neither a forecast nor a projection; rather it is a description of the rate of building permits, housing starts, housing completions, or new home sales in the particular month for which they are calculated.
Data labeled "Not Seasonally Adjusted" refers to the fact that the data are not adjusted for seasonality using seasonal adjustment and not shown at an annual rate.
– The single-family statistics include fully detached, semidetached (semiattached, side-by-side), row houses, and townhouses. In the case of attached units, each must be separated from the adjacent unit by a ground-to-roof wall in order to be classified as a single-family structure. Also, these units must not share heating/air-conditioning systems or utilities, such as water supply, power supply, or sewage disposal lines.
Units built one on top of another and those built side-by-side that do not have a ground-to-roof wall and/or have common facilities (i.e., attic, basement, heating plant, plumbing, etc.) are not included in the single-family statistics.
– Measure of the variation among the estimates from all possible samples; measure of the precision with which an estimate from a particular sample approximates the average results of all possible samples; square root of the sampling variance.
Structure, Type of
– The statistics, by type of structure, refer to the structural characteristics of the building.
The one-unit structure category is a single-family home. It includes fully detached, semidetached (semiattached, side-by-side), row houses, and townhouses (see "Single-Family House".)
Multifamily structures are classified by the number of housing units in the structure.
Data are tabulated for 2 units, 3 and 4 units combined, and 5 or more unit structures.
– For State data: Not seasonally adjusted; For MSA data: Not seasonally adjusted and not weighted.
Universe (Building Permits Survey)
– For estimates of housing units authorized from the Building Permits Survey, the "Universe" is defined as all unique permit offices at the time the last sample was selected. "Unique" permit offices are those jurisdictions that would not result in double reporting. For example, if a city issues zoning permits and its county issues building permits (including permits for buildings in the city), only the county office is included in the universe. The numbers associated with the various universes (e.g., 20,000-place universe) are rounded for ease of identification:
20,000-place universe - jurisdictions identified as of 2003
19,000-place universe - jurisdictions identified as of 1993
17,000-place universe - jurisdictions identified as of 1983
16,000-place universe - jurisdictions identified as of 1977
14,000-place universe - jurisdictions identified as of 1971
13,000-place universe - jurisdictions identified as of 1966
10,000-place universe - jurisdictions identified as of 1958