The data for tenure were obtained from Housing Question 17 in the 2006 American Community Survey. The question was asked at occupied housing units. Occupied housing units are classified as either owner occupied or renter occupied.

A housing unit is owner occupied if the owner or co-owner lives in the unit even if it is mortgaged or not fully paid for. The owner or co-owner must live in the unit and usually is Person 1 on the questionnaire. The unit is "Owned by you or someone in this household with a mortgage or loan" if it is being purchased with a mortgage or some other debt arrangement such as a deed of trust, trust deed, contract to purchase, land contract, or purchase agreement. The unit also is considered owned with a mortgage if it is built on leased land and there is a mortgage on the unit. Mobile homes occupied by owners with installment loan balances also are included in this category.
A housing unit is "Owned by you or someone in this household free and clear (without a mortgage)" if there is no mortgage or other similar debt on the house, apartment, or mobile home including units built on leased land if the unit is owned outright without a mortgage.

All occupied housing units which are not owner occupied, whether they are rented or occupied without payment of rent, are classified as renter occupied. "No cash paid" units are separately identified in the rent tabulations. Such units are generally provided free by friends or relatives or in exchange for services such as resident manager, caretaker, minister, or tenant farmer. Housing units on military bases also are classified in the "No cash paid" category. "Rented for cash rent" includes units in continuing care, sometimes called life care arrangements. These arrangements usually involve a contract between one or more individuals and a health services provider guaranteeing the individual shelter, usually a house or apartment, and services, such as meals or transportation to shopping or recreation. (For more information, see " Meals Included in Rent .")

From 1996-2006 the American Community Survey questions were the same. Starting in 2006, the instruction Mark (X) ONE box. was added following the question, and the instruction Include home equity loans. was added following the response category "Owned by you or someone in this household with a mortgage or loan?" Additional changes introduced In 2006 included revising the wording of two of the response categories from "Rented for cash rent?" to "Rented?" and "Occupied without payment of cash rent?" to "Occupied without payment of rent?"

The detailed tables provide basic distributions of characteristics. They are the foundation upon which other data products are built. These tables display estimates and the associated lower and upper bounds of the 90 percent confidence interval. They include demographic, social, economic, and housing characteristics, and provide 1-, 3-, or 5-year period estimates for the nation and the states, as well as for counties, towns, and other small geographic entities, such as census tracts and block groups.

The Census Bureau's goal is to maintain a high degree of comparability between ACS detailed tables and Census 2000 sample-based data products. In addition, characteristics not measured in the Census 2000 tables will be included in the new ACS base tables. The 2007 detailed table products include more than almost 600 tables that cover a wide variety of characteristics, and another 380 race and Hispanic-origin iterations that cover 40 key characteristics. In addition to the tables on characteristics, approximately 80 tables summarize allocation rates from the data edits for many of the characteristics. These provide measures of data quality by showing the extent to which responses to various questionnaire items were complete. Altogether, over 1,300 separate detailed tables are provided.

Both occupied and vacant mobile homes to which no permanent rooms have been added are counted in this category. Mobile homes used only for business purposes or for extra sleeping space and mobile homes for sale on a dealer's lot, at the factory, or in storage are not counted in the housing inventory.

This is a 1-unit structure detached from any other house, that is, with open space on all four sides. Such structures are considered detached even if they have an adjoining shed or garage. A one-family house that contains a business is considered detached as long as the building has open space on all four sides. Mobile homes to which one or more permanent rooms have been added or built also are included.

This is a 1-unit structure that has one or more walls extending from ground to roof separating it from adjoining structures. In row houses (sometimes called townhouses), double houses, or houses attached to nonresidential structures, each house is a separate, attached structure if the dividing or common wall goes from ground to roof.

These are units in structures containing 2 or more housing units, further categorized as units in structures with 2, 3 or 4, 5 to 9, 10 to 19, 20 to 49, and 50 or more apartments.

This category is for any living quarters occupied as a housing unit that does not fit the previous categories. Examples that fit this category are houseboats, railroad cars, campers, and vans. Recreational vehicles, boats, vans, tents, railroad cars, and the like are included only if they are occupied as someone's current place of residence.

The 1996-1998 American Community Survey question provided the response category, "a mobile home or trailer." Starting in 1999, the ACS response category dropped "or trailer" to read as "a mobile home."

SPPs provide certain characteristics from the data profiles for a specific race or ethnic group (e.g., Alaska Natives) or some other selected population group (e.g., people aged 60 years and older). SPPs are provided every year for many of the Census 2000 Summary File 4 iteration groups. SPPs were introduced on a limited basis in the fall of 2005, using the 2004 sample. In 2008 (sample year 2007), this product was significantly expanded. The earlier SPP requirement was that a substate geographic area must have a population of at least 1,000,000 people. This threshold was reduced to 500,000, and congressional districts were added to the list of geographic types that can receive SPPs. Another change to SPPs in 2008 is the addition of many country-of-birth groups. Groups too small to warrant an SPP for a geographic area based on 1 year of sample data may appear in an SPP based on the 3- or 5-year accumulations of sample data. More details on these profiles can be found in Hillmer (2005), which includes a list of selected race, Hispanic origin, and ancestry populations.

Research has shown that respondents tended to overstate their expenses for electricity and gas when compared to utility company records. There is some evidence that this overstatement is reduced when yearly costs are asked rather than monthly costs. Caution should be exercised in using these data for direct analysis because costs are not reported for certain kinds of units such as renter-occupied units with all utilities included in the rent and owner-occupied condominium units with utilities included in the condominium fee.

The American Community Survey questions ask for monthly costs for electricity and gas, and yearly costs for water/sewer and other fuels. Since 1999, the words "or mobile home" were added to each question, and Question 14b, which asked "Last month, what was the cost of gas for this house, apartment, or mobile home?" had an additional response category, "included in electricity payment entered above."

Once plans are finalized for the ACS data products, the DRB reviews them to assure that confidentiality of respondents has been protected.

Title 13 of the United States Code (U.S.C.) is the basis for the Census Bureau's policies on disclosure avoidance. Title 13 says, "Neither the Secretary, nor any other officer or employee of the Department of Commerce may make any publication whereby the data furnished by any particular establishment or individual under this title can be identified . . ." The DRB reviews all data products planned for public release to ensure adherence to Title 13 requirements, and may insist on applying disclosure avoidance rules that could result in the suppression of certain measures for small geographic areas. (More information about the DRB and its policies can be found at . To satisfy Title 13 U.S.C., the Census Bureau uses several statistical methodologies during tabulation and data review to ensure that individually identifiable data will not be released.

These are vacant units offered "for rent," and vacant units offered either "for rent" or "for sale."

These are vacant units rented but not yet occupied, including units where money has been paid or agreed upon, but the renter has not yet moved in.

These are vacant units being offered "for sale only," including units in cooperatives and condominium projects if the individual units are offered "for sale only." If units are offered either "for rent" or "for sale" they are included in the "for rent" classification.

These are vacant units sold but not yet occupied, including units that have been sold recently, but the new owner has not yet moved in.

These are vacant units used or intended for use only in certain seasons or for weekends or other occasional use throughout the year. Seasonal units include those used for summer or winter sports or recreation, such as beach cottages and hunting cabins. Seasonal units also may include quarters for such workers as herders and loggers. Interval ownership units, sometimes called shared-ownership or time-sharing condominiums, also are included here.

These include vacant units intended for occupancy by migratory workers employed in farm work during the crop season. (Work in a cannery, a freezer plant, or a food-processing plant is not farm work.)

This chapter deals with the 1-year and 3-year data products. Future versions of this document will include a discussion of the 5-year data products. The American Community Survey (ACS) data products and supporting documentation are released in several series and at several Internet locations. The primary Web site for data dissemination is the American FactFinder (AFF); supporting documentation can be found on the ACS Web site and the Census Bureau's File Transfer Protocol (FTP) site.

Since 2000, the ACS has been tabulating and publishing single year estimates for specific areas with populations of 250,000 or more. In 2005, the ACS expanded its sample size to cover all of the United States and the Commonwealth of Puerto Rico. In summer 2006, the ACS started releasing data annually for areas with populations of 65,000 or more. In 2008, the ACS is releasing 3-year period estimates for areas with a population of 20,000 or more on an annual basis. For smaller areas, it will take 5 years to accumulate a large enough sample to produce releasable estimates. Once those data are collected, the Census Bureau will release tabulations annually, based on 5-year period data for areas as small as census tracts and block groups.

Federal agencies distribute billions of dollars among states, tribal governments, and population groups, based on social and economic data. In the past, the statistics that determined services locations and program funding came in large part from the long-form sample of the decennial census. As the ACS continues to grow, its data products will provide updated versions of many of the long-form products from Census 2000. Beginning in 2010, the decennial census no longer will include a long-form sample, and ACS data products will provide high-quality, updated annual statistics for comparisons of the demographic, social, economic, and housing characteristics of areas and population groups. The ACS statistics also will show trends and relative differences between areas and population groups. These data products will continue to meet the needs of those who previously used the decennial census sample statistics, and will provide more current statistics than those available from the census long-form sample, which reflect only one point in time.

By 2010, the information on social, demographic, economic, and housing characteristics previously available only once every 10 years will be available annually through the ACS for all areas. Each year thereafter, these areas will get new estimates based on the 5-year interval ending in the latest completed sample year.

Figure 14.1 summarizes the data products release schedule. In 2006, the first set of 1-year estimates was released for specific areas with populations of 65,000 and more. These areas will continue to receive 1-year estimates annually. In 2008, data collected over a 3-year period (2005− 2007) was released for areas with at least 20,000 people. These areas will continue to receive 3-year estimates annually. In 2010, the first 5-year products will be released based on data collected in 2005−2009. These products will be produced for areas down to census tracts and block groups. Once 3- and 5-year products are produced, annual updates will follow, as indicated by Table 14.1.arThe AFF Web site contains data maps, tables, and reports from a variety of censuses and surveys.
AFF lists these data sets by program areas and survey years. AFF contains data for a wide variety
of surveys including the Decennial Census, the ACS, the Population Estimates Program, the Economic
Census, and the Annual Economic Surveys.

Data product	Population threshold	Year of data release
		2006	2007	2008	2009	2010	2011	2012	2013
1-year estimates	65,000+	2005	2006	2007	2008	2009	2010	2011	2012
3-year estimates	20,000+			2005-	2006-	2007-	2008-	2009-	2010-
				2007	2008	2009	2010	2011	2012
5-year estimates	All areas*					2005-	2006-	2007-	2008-
						2009	2010	2011	2012

* All legal, administrative, and statistical geographic areas down to the tract and block group level.

The AFF Web site contains data maps, tables, and reports from a variety of censuses and surveys. AFF lists these data sets by program areas and survey years. AFF contains data for a wide variety of surveys including the Decennial Census, the ACS, the Population Estimates Program, the Economic Census, and the Annual Economic Surveys.

The AFF is the primary Web access tool for ACS data. Data products include detailed tables, data profiles, comparison profiles (1-year data only), narrative profiles, ranking tables and charts (single year data only), geographic comparison tables, thematic maps, subject tables, selected population profiles, and downloadable public use microdata sample (PUMS) files.

The ACS Web site contains a wealth of information, documentation, and research papers about ACS. The site contains important metadata, including more than 50 population concept definitions and more than 40 housing concept definitions. The ACS Web site can be found at .

Documentation on the accuracy of the data also is included, and provides information about the sample design, confidentiality, sampling error, nonsampling error, and estimation methodology. The errata section lists updates made to the data. The geography section gives a brief explanation of the Census Bureau's geographic hierarchy, common terms, and specific geographic areas presented.

The FTP site is intended for advanced users of census and ACS data. This site provides quick access to users who need to begin their analyses immediately upon data release. The data are downloaded into Excel, PDF, or text files. Users of the FTP site can import the files into the spreadsheet/database software of their choice for data analysis and table presentation. Documentation describing the layout of the site in the README file is available in the main directory on the FTP server. The FTP site can be accessed through the ACS Web site.

The data on plumbing facilities were obtained from Housing Question 9 in the 2006 American Community Survey. The question was asked at both occupied and vacant housing units. Complete plumbing facilities include: (a) hot and cold running water, (b) a flush toilet, and (c) a bathtub or shower. All three facilities must be located inside the house, apartment, or mobile home, but not necessarily in the same room. Housing units are classified as lacking complete plumbing facilities when any of the three facilities is not present.

The 1996-2006 American Community Survey questions were stand-alone questions that asked the respondent to answer either Yes, has all three facilities or No to the question of whether the housing unit had complete plumbing facilities, requiring that the facilities all be in the same unit. Starting in 2006, the structure of the question changed and combined plumbing facilities with kitchen facilities and telephone service availability into one question to ask, Does this house, apartment, or mobile home have - and provided the respondent with a Yes or No checkbox for each component needed for complete facilities. An additional change introduced In 2006 included changing the description of the component hot and cold piped water to hot and cold running water.

'Occupants per room' is obtained by dividing the number of people in each occupied housing unit by the number of rooms in the unit. The figures show the number of occupied housing units having the specified ratio of people per room. Although the Census Bureau has no official definition of crowded units, many users consider units with more than one occupant per room to be crowded. 'Occupants per room' is rounded to the nearest hundredth.