Frequently Asked Questions

Note: These “frequently asked questions” accompanied our 2013 State of Healthy Housing report.

Which metropolitan areas have the most healthy and least healthy housing conditions?
Best MSA: The metro areas of San Jose, CA: Indianapolis, IN; Tampa-St Petersburg-Clearwater, FL; Anaheim-Santa Ana, CA; and Phoenix, AZ. Worst MSA: The metro areas of Memphis, TN; Birmingham, AL; San Antonio, TX; and Oklahoma City, OK.

Which central cities have the most healthy and least healthy housing conditions?
Best central cities: San Jose, CA; Fort Worth-Arlington, TX, Phoenix, AZ, San Bernardino-Riverside and San Diego, CA, have the healthiest housing.
Worst central cities: Birmingham, AL, and Detroit, MI, have the least healthy housing.

How were the data for the study collected?
The study uses data from the American Housing Survey (AHS), which is conducted by the U.S. Bureau of the Census for the U.S. Department of Housing and Urban Development. The results and details are available at The AHS collects the following data:

  • Individual household characteristics
  • Owner/renter’s income
  • Housing and neighborhood quality
  • Housing costs
  • Equipment and fuels
  • Size of housing unit
  • Recent moves.

National data are collected in odd-numbered years, and data for a subset of the nation’s Metropolitan Areas are collected approximately every two years. The AHS returns to the same housing units to gather data, while regularly adding units to represent new construction. The stated goal of the U.S. Department of Housing and Urban Development (HUD) is to sample each of the 46 Metro areas every six years, but because of budget constraints, some areas have not been sampled in over 10 years. The years of the Metro surveys included in this report are 1998, 2002, 2003, 2004, 2007, 2009, and 2011. The survey includes apartments, single-family homes, mobile homes, and vacant homes; for this report, data were limited to occupied dwellings.

Why isn’t my city listed?
The U.S. Census Bureau produces a Metro Edition of the American Housing Survey for a subset of 46 of the nation’s larger Metropolitan Statistical Areas, which are the same metro areas we cover in our rankings. Rochester, NY, which has not been sampled since 1998, is not included in the rankings because the data is more than 15 years old. All other Metro areas were sampled in 2002 or more recently.

Why aren’t serious problems (such as cockroaches, missing/inoperable smoke alarms, scalding hot water, and other housing problems) ranked?
The AHS does not have questions for every housing hazard, such as cockroaches, but we used as much of the data collected as we could. An overarching goal of the State of Healthy Housing is to increase interest and understanding of housing-related health hazards and to increase the size and scope of the American Housing Survey, which is the source of data for the study. We are advocating for increased funding for AHS to (1) include additional health-related questions in the survey, (2) ensure that the surveys are conducted according to the schedule set by HUD, and (3) to ensure that sufficient data are collected from each jurisdiction to enable rigorous analysis.

What’s the difference between the “Basic Housing” and the “Healthy Housing” indicators?
“Basic Housing” covers the basic structure and systems that provide the minimally acceptable functions of housing, including plumbing, heating, electrical, kitchen, hallways, and upkeep. The score is the percent of homes with severe or moderate physical housing problems. Severe and moderate physical problems are defined by AHS. See Table 1 below for more information.

“Healthy Housing” assesses specific, significant health and safety hazards in the home, such as signs of rats, inoperable toilets, and peeling paint (a major factor in childhood lead poisoning). Twenty housing characteristics make up the healthy housing indicator.

How are the “Basic Housing” rankings calculated?
To assess basic housing quality, NCHH ranks each community by the percentage of homes with severe or moderate housing problems. If the percentage of severe or moderate housing problems for a community is statistically significantly different than the concurrent national percentage, the community is designated as Most Healthy or Most Unhealthy.

How are the “Healthy Housing” rankings calculated?
The Healthy Housing rankings were developed using a composite score of the 20 healthy housing characteristics. For every community, the 20 housing characteristics are assigned a value of -1 (significantly better than concurrent national average), 0 (not significantly different from the national average), or 1 (significantly worse than the national average). The values are totaled to create a healthy housing score for each community (-20 being best and 20 worst). The communities are ranked based on their scores. A score of 0 is considered average.

We classified the communities as follows:
Score of 8 or higher MOST UNHEALTHY
Score between 7 and -3 FAIR
Score of -4 or lower MOST HEALTHY

How did you decide which housing characteristics to analyze?
We selected housing characteristics from the U.S. Census Bureau’s American Housing Survey that either directly or indirectly impact health or safety. The characteristics are largely based on the federal “housing quality standards,” which set forth the requirements for decent, safe, and sanitary conditions in federally-owned or assisted housing. The AHS has been collecting information on these variables for over 30 years using a validated survey protocol. Based on expert opinion and in some cases, documented research, all of the characteristics selected can be expected to adversely affect the health of the residents.

Are some housing characteristics weighted more heavily than others in the analysis?
No. The 20 housing characteristics are given equal weight. We currently lack adequate information to demonstrate that any particular housing characteristic is more hazardous and deserves extra weighting.

What are the most common problems across the nation in 2011?
The most common problems were water leaks from the outside (11%) and inside (9%), signs of mice (10%). roofing problems (5%), damaged interior walls (5%), and foundation problems (5%)

What is NCHH doing about all this?

  • Research: NCHH conducts cutting-edge research to identify not only problems but also best practices and solutions. Please see to learn more about NCHH’s research.
  • Information and Materials: NCHH produces content and educational materials for consumers, professionals, and public decision makers. If after reviewing NCHH’s resources section you have additional questions, please visit “Ask NCHH” at
  • Training: Each year, the National Healthy Homes Training Center and Network trains thousands of housing, health, and other professionals on how to build and maintain healthier housing.
  • Policy/Advocacy: We are fighting for stronger legislation, regulations, and enforcement by Congress, federal and state agencies, and other key bodies. Please see for more information.

Why aren’t the data all from the same year?
Unlike the national American Housing Survey data that are published every two years, a consistent pattern of publication for the “Metro Edition” covering these 46 metro areas has declined in recent years. Previously, the Census Bureau’s website says the Metro surveys are supposed to be done every six years. However, the Bureau recently revised the plan to specify that Metro surveys will be done every four years. We expect that 2013 survey will include all metro areas not sampled in 2009 or 2011.

Wouldn’t jurisdictions with older data be unfairly penalized?
To ensure that locations were not penalized in the rankings for having older data, we compared each jurisdiction’s data to the most similar national year of data.

How was the survey conducted (e.g., number of people, site visits versus phone, repeat visits)?
The initial surveys are conducted through in-depth, face-to-face interviews with the homeowner or renter. Subsequent surveys are conducted by phone.

Why do many of the metrics have numerical rankings but don’t have “healthy” or “unhealthy” icons?
Only conditions that are significantly different statistically from the national average for a given survey year are noted with a green or red house icon.

How can my city make use of this data?
Municipal governments can use this data to engage in the following activities:

  • Use information to demonstrate need for healthy housing code enforcement
  • Present information to other agencies within government to start dialogue on healthy housing issues
  • Review strengths and areas for improvement with news outlets — demonstrate how the city has started to address housing problems or where they need more support

NGOs and community groups should use the State of Healthy Housing for the following activities:

  • Analyze data for strategic planning and areas to focus on
  • Present information to government agencies
  • Encourage more frequent, detailed data collection similar to this
  • Provide educational materials and resources to community members on housing hazard of concern