In the midst of the local real estate boom between 2003 to 2007, the buzz-phrase for home buyers was “drive to affordability.” It fueled demand for homes in suburban cities such as Issaquah and Sammamish from professionals working in bigger centers, such as Seattle, Bellevue and Tacoma.

But according to a new study published by the Chicago-based Center For Neighborhood Technology (CNT), this “drive to affordability” concept is having less traction with buyers, who are growing more conscious of the financial, social, and environmental costs of living many miles from where they work.

Using online mapping technology, the Housing and Transportation Affordability Index uses Census 2000 data to factor in transportation costs as a key component of housing affordability.

Based on the traditional assumption that most Americans aim to spend about 30 percent of their personal income on housing, the study illustrates how transportation costs can significantly affect the real cost of living in a certain area. CNT suggests that no more than 45 percent of an individual’s personal income should be spent on both transportation and housing.

The online CNT map covers 337 metro regions — including the Seattle-Bellevue-Everett Metropolitan Area, which includes Issaquah and Sammamish — and 161,000 neighborhoods, representing 80 percent of the U.S. population.

The mapping shows areas considered “affordable” — based on the median percentage of household income spent on housing — in yellow, while areas above the 45 percent portion are shown in blue. When transportation costs are added to housing costs, many areas in this broad geographic region jump into the unaffordable category.

CNT spokesperson Nicole Gotthelf said her organization was trying to give readers information on how to make economic housing decisions, especially during a recession when every dollar counts.

“We’re trying to show that lower transportation costs together with a compact, walkable neighborhood make an affordable community,” she said.

An interactive map on display at their Web site, http://htaindex.cnt.org/, takes into account average household size, income, neighborhood density, connectivity, local jobs, average commute time and a few other factors to determine total transportation costs.

The new CNT analysis shows that only two in five American communities — just 39 percent — are affordable for typical households when their transportation costs are considered along with housing costs.

As a job center, and a member of the Cascade Agenda Leadership Cities, the CNT map shows almost all of the Issaquah valley floor in affordable yellow, amidst a sea of unaffordable blue. Unfortunately, the Census data doesn’t take into account changes in city planning and construction in the last decade which saw significant changes that would present Issaquah as even more affordable and transit friendly, including Issaquah’s two transit centers, the completion of the compact Issaquah Highlands neighborhood and the adoption of a Complete Streets ordinance.

No Sammamish neighborhood is considered affordable by any of the study’s metrics.

Local transportation advocate Jeff Youngstrom, head of Getting Around Issaquah Together (GAIT), told The Reporter this week that while the map of Issaquah and Sammamish isn’t particularly illuminating, he noted with interest that Squak Mountain looks inexpensive until transportation costs are added in.

Youngstrom said he came to the same conclusion years ago when he and wife were house hunting and decided to spend more for a home in Olde Town, down on the valley floor, where transporation costs were lower.

He said the same was true of suburban areas such as Maple Valley, Covington or Enumclaw and said local residents suffer as a result of the commuter traffic and pollution headaches running along Front Street and Issaquah-Hobart Road.

“That is a really cool Web site,” he said. “It’s heartening to see this kind of analysis putting the lie to the old ‘drive til you qualify’ rule of real estate. That kind of thinking just results in time and money wasted sitting in traffic that otherwise wouldn’t exist.”

Transportation costs can add up for households and communities. CNT estimates transportation costs can range from 15 percent of household income in location efficient neighborhoods to over 28 percent in inefficient locations.

The online tool also shows fluctuations in cost associated with gas prices and Greenhouse gas emissions, and can be customized by users to measure household reliance on costly, carbon-intensive automobile travel.