When transportation costs are factored into the affordability equation, only two in five U.S. communities offer affordable housing options for average households in the nation, according to a new analysis by the Center for Neighborhood Technology (CNT).

The Center’s Housing + Transportation (H + T) Affordability Index, unveiled this week, provides a snapshot of neighborhood affordability based on combined housing and transportation costs for 337 metro areas across the country.

According to the report, the traditional definition of housing affordability is that 30 percent or less of household income is spent on housing. “But in almost all metro regions of the country, when the definition of affordability includes both housing and transportation costs – at 45 percent of income – the  number of communities affordable to households earning the area median income decreases significantly.”

Increasing gas prices, combined with longer commutes, have led many families who believed they were saving money on housing costs by moving to outer-ring suburbs to actually spend more money than their urban counterparts.

Looking for affordability data for a particular metro area? The H + T Affordability Index website provides an interactive mapping tool that allows users to compare the “true costs” associated with living in specific communities within a metro area.

The Center for Neighborhood Technology, established in 1978, is a “think-and-do tank” that promotes urban sustainability. Its goal is to simultaneously improve the environment, strengthen the economy, and advance equity through the effective use of existing resources and community assets.

Housing Affordability by Metro Area

The Center for Neighborhood Technology H + T Affordability Index is designed to give a more accurate representation of the costs associated with living in specific community. Because “affordability is about more than home price,” the H + T Index also incorporates transportation costs based on access to local services, commute time, gas prices, and transit options, among other variables.

The traditional definition of housing affordability is that 30 percent or less of household income is spent on housing. But factoring in transportation costs can make a difference between affordable and well, less affordable communities.

The following examples show the percentage of communities with affordable housing based on the standard “30-percent-of-income” rule, compared to the combined “45-percent-of-income” that includes both transportation and housing.

Percentage of Communities in Selected Metro Areas Considered Affordable 

Metro Area Housing

(30% of income)

Housing + Transportation

(45% of income)

Boston 64% 52%
Chicago 68% 52%
Cleveland 72% 46%
Houston 79% 55%
Pittsburgh 72% 32%

Source: Center for Neighborhood Technology H + T Affordability Index Fact Sheet