An often noted stereotype of housing claims that owner-occupied homes are smaller in downtown areas and inner suburbs and grow in size as you move out to the outer suburbs. There is an element of truth to this description of the housing stock, but it also overlooks how many people actually reside in these homes. That is, it is incorrect to claim that those larger homes mean more “housing space” for people who live outside central cities. Why? Family size.
Home Owners across Metropolitan Statistical Area Locations
The American Housing Survey (AHS), funded by the Department of Housing and Urban Development and conducted by the Census Bureau once every two years, provides sufficient data to estimate and compare the median size of owner-occupied homes across different locations. The AHS identifies whether a particular housing unit is located inside or outside metropolitan statistical area (MSA). MSAs are contiguous counties (or towns in New England) that are defined according to commuting patterns. In addition, for homes inside MSAs, the AHS specifies whether the home is in a central city, which may include not only the largest city but other cities above Census population or employment requirements. Following a convention used in the printed volumes of the AHS, areas inside an MSA but not in a central city are called suburbs.
Suburbs can be classified as urban or rural, based primarily on Census population and density thresholds. The term urban was introduced and defined by the Census Bureau to capture areas that were densely built-up whether or not they were part of a particular legal jurisdiction. By definition, areas not classified as urban are rural. The AHS public use file is still based on 1980 geography, so urban suburbs as defined in this paper consist of areas that were located within a metropolitan area and densely settled as of 1980. Although there is no universally accepted set of definitions, urban suburbs based on this criterion may be a reasonable working definition of what most people mean when they use a phrase like “inner” suburbs. Rural suburbs, and possibly in some cases non-metropolitan areas, would then approximate the outlying areas or “exurbs.”According to the 2009 AHS, the most recent data available, the majority, three quarters, of more than 76 million owner- occupied homes are concentrated inside metropolitan areas and the remaining quarter are spread out outside MSAs (Chart 1). Urban areas outside central cities are home to more than 27 million owning-households and account for more than one-third of all owner-occupied units. Central cities account for additional 17.2 million units, or almost a quarter of owner-occupied units. Rural metropolitan areas house 13 million owning- households and, thus, account for the smallest share, 17%.
Table 1 looks at the median size of owner-occupied homes across different locations and also provides some basic information about households occupying these units. The results confirm, in part, the stereotype - owner-occupied homes grow in size as one moves from the central city, to the suburbs and rural areas of MSAs. Nationwide, the median square footage of an owner-occupied home is 1,800 square feet. Homes in the central city are about 7%, on average smaller, at 1,678 square feet. The median for homes in urban areas outside the central city is equal to the national median of 1,800 square feet, while those in rural MSA areas is larger still at 1,900 square feet.
However, a closer look at the Table 1 data reveals that not only do homes grow in size when one moves away from the central city to suburbs but households grow in size as well. The average number of people per home increases from 2.6 in central cities to 2.7 in urban and rural MSA areas. Furthermore, metropolitan families choosing larger houses outside of central cities are more likely to have school-age children. Only one-third of households living in central cities have children under 18, which is below the US average of 34 percent. Moreover, families in urban and rural areas of MSAs are more likely to have children than households in other areas, with 37% of urban MSA households and 36% of rural MSA households having children.
Chart 2 examines the locations of households with and without school-age children and provides further evidence that larger families are more likely to lie outside central cities. Nationwide, there are 26 million households with children under the age of 18. More than half of these households reside in metropolitan suburbs (39 percent in urban areas and 18 percent in rural areas of MSAs). Only 22 percent of home owners with children choose central cities as their home. Again, consistent with intuition, we find that households with one or more children are more likely to live in MSAs, but not the central city itself.
Consistent with the findings that central cities are more likely to have home owners without children and smaller size households, the AHS data show that condominiums (defined as owned multifamily apartments) are more common in central cities. While the national share of condos is about 5 percent, their share is more than double that in central cities, 11 percent. The concentration of owned apartments in urban MSA areas matches the national average. In sharp contrast, the share of condominiums in rural MSA areas and outside of MSAs is negligible 1 percent.
The last column of Table 1 presents differences in home and household size into more meaningful comparisons of square footage per person. Looking at these home sizes on a per-person basis challenges the stereotyped view of large homes in the suburbs. Nationally, the median square footage per person in owner-occupied homes is 800 square feet. And this is exactly the median size for the urban and rural parts of metropolitan areas and areas outside MSAs. Median square footage per person is somewhat smaller for central cities (767), but only by 4% - less than the 7% difference seen on the total house size between central cities and the national median.
Additional AHS data in Table 2 provide further insights into the distribution of home owners by household size as well as their geographic locations. The two-person household is the most common type in the United States and accounts for more than 36 percent or 27.6 million of home owners. Although, combining larger households with three or more people together produces the largest grouping with 32 million or almost 42 percent of home owners.
Not surprising, the AHS data indicate that single person households are concentrated more densely in central cities. While the share of single person home owners in the United States is 22 percent, their share in central city locations of MSAs is close to 26 percent. On the other hand, the share of single person households in rural parts of MSAs is less than 18 percent. Two person households that are most prevalent in the United States account for 36 percent of all home owners. However, their share in central cities and urban parts of MSAs is only 34 percent. Households with three, four or five people living in metro areas are much more common outside of central cities. For example, four person households account for almost 18 and 17 percent of home owners in urban and rural parts of MSAs respectively, while their share in central cities is only 14 percent. An interesting exception to these general trends is the six or more household class – their density is just as high in central cities as in urban parts of MSAs and exceeds those for rural and areas outside MSAs.
The AHS data also allow for comparison of homes across four Census regions. The data reveal regional differences in both home size and per person square footage. In general, on a median basis, homes in the Northeast tend to be smaller and homes in the South tend to be larger than the national averages. For example, consider the averages for owner-occupied homes in central cities across regions. The national median is 767 square feet. Homes in central city areas in the northeast have a median of 667 square feet (15% below the national average) and homes in the south have a median of 850 square feet (27% higher).
In part, house age explains these regional differences. The median age of an owner-occupied home in the northeast is 51 years, while the median age of a home in the south is only 31 years (it is 41 and 49 for the Midwest and West respectively). Newer homes are on average going to be larger. The median size of new single-family homes completed increased regularly from 1,520 square feet in 1982 to a maximum of 2,277 in 2007. 
The following charts present the data for the four national regions, as reported by the 2009 AHS. Just as in case of the national data, the regional data show that homes tend to grow in size as one moves away from central cities into less densely populated areas. The exception is the South region, where rural metropolitan homes are, on a median basis, smaller than urban metropolitan homes that are outside of central cities. These differences get smaller and often go away when comparing home sizes on a per person base. In the South region, it turns out that central city homes have higher per person square footage than suburban homes. And in the West, square footage per person is the same in homes in central cities and urban areas outside of central cities.
The following table examines these regional differences just for homes located in central cities and rural suburban areas respectively. In general, central cities have the smallest homes, and rural suburbs have the largest homes, so this comparison examines the largest differences in home size by geography. Indeed, the table effectively demonstrates that for most of the U.S., once size per person is calculated, most of the differences in home size are significantly reduced. A notable exception would be the Northeast, where the housing stock is older and it is more difficult to build new homes in well established areas.
This analysis of the 2009 American Housing Survey data suggests that the stereotype of the large suburban home is misleading and criticisms of larger homes are misguided. The AHS data indicate that while there are some regional differences on a per-person basis, the size of owner-occupied homes is in part determined by the number of people a home contains. And larger homes contain more people. And, typically, larger homes are found in the types of places where larger households (i.e. families with children) tend to live – suburbs of metropolitan areas.
 According to the AHS, “Excluded from the calculation of square footage are unfinished attics, carports, attached garages, porches that are not protected from weather (such as screened porches), and mobile home hitches. Both finished and unfinished basements are included.”