Greenest homes are those near public transit

Location, location, location -- it's a well-worn mantra in real estate. New research shows yet another reason why it's important: it decides how green a home really is. Housing near public transportation uses less energy than homes in the suburbs, even Energy Star-rated ones.

That's the finding of a study released this week by the U.S. Environmental Protection Agency, which supported the data analysis. The EPA says location is vital because buildings and transportation together account for about 70% of U.S. energy use and 62% of its greenhouse gas emissions.

"People can do many things to reduce their energy use: install energy-efficient light bulbs, carpool or walk or buy Energy Star appliances, among other things. But the way in which we plan and build our communities also has a significant role to play in creating a more environmentally and economically sustainable future," EPA said in announcing the results.

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The study compares the total energy use of various kinds of housing in conventional suburbs vs. "transit oriented" developments, including the energy used for heating and cooling the home as well as for transporting its residents. It found homes in walkable neighborhoods near public transit were "location efficient" because residents didn't need to drive as much.

The results are dramatic but hardly surprising.

For example, single-family homes in a conventional U.S. suburb use an average of 108 million BTUs (British Thermal Units--a measure of energy consumption) per year for heating, cooling, lighting and appliances. Its residents also use 132 million BTUs per year for transportation. This totals 240 million BTUs.

But if the same home were located in a "transit-oriented development," its residents would use only 39 million BTUs per year for transportation so the home's total energy consumption would fall to 147 million BTUs.

This would be even less than the total 158 total BTUs that an Energy Star-rated house (at least 20% more efficient than regular new homes) in the suburbs would consume each year.

"It's little surprise, then -- especially with gasoline prices trending upward -- that real estate values in transit-oriented areas have been holding their own or rising, while real estate values in automobile-dependent suburbia have been falling," writes Alex Wilson, executive editor of Environmental Building News.

Wilson notes that in the 2010 book, Foreclosing the Dream: How America's Housing Crisis is Changing Our Cities and Suburbs, University of Virginia architecture professor William Lucy shows that foreclosures in 2008 and 2009 occurred more often in car-dependent outer suburbs than in cities and closer-in suburbs.

The EPA-supported study was conducted by Jonathan Rose Companies, which has long touted "smart growth." It comes as the Obama administration is trying to promote walkable neighborhoods. In June 2009, the EPA created an inter-agency, Partnership for Sustainable Communities with the Department of Housing and Urban Development and Department of Transportation.