Location matters when building green

EPA report shows the relative importance of “location efficiency” versus “energy efficiency”.

Alex Wilson of the excellent blog BuildingGreen.com just reported on a recent EPA study that points out that “where we build can be even more important than how we build.”

The study, conducted by Jonathan Rose Companies for the EPA, shows that while the average suburban American house consumes 108 million BTUs per year in home energy use, it also consumes a whopping 132 million BTUs per year in transportation energy use, for a total of 240 million BTUs per year.  That means that 55% of the total energy use of a typical suburban house goes to transportation, and just 45% to heating, cooling, and operating the house.  Now place that same house in a transit oriented development (or “TOD” in urban planner’s parlance) and transportation energy use drops to just 39 million BTUs per year, for a total home energy use of 147 million BTUs per year, a big decrease compared to its conventional suburban counterpart.

Image: Jonathan Rose Companies

Careful examination of the chart above suggests that locating a house in a transit oriented development has a bigger  impact on total home energy use than building “green”.  We’re loathe to carry this argument too far.  After all, the EPA study pegs a “green” home at just 20% more efficient than a conventional home, which pales in comparison to the 85-90% energy savings of a Passive House.  So the study’s modest definition of “green” is a bit misleading for comparisons to conventional construction.

Nevertheless, there’s no question that we should be shifting toward transit-friendly, pedestrian-friendly, vibrant urban neighborhoods and away from conventional, sprawling suburbs.  Perhaps we as a society should apply the same zeal to maximizing the “location efficiency” of homes as we do to maximizing their energy efficiency.

For more on the topic, check out these Field Notes blog posts:
Green Buildings Don’t Force You To Drive
Don’t Let Green Structures Go Gray
What’s Your Home’s Walk Score?
Accessory Dwelling Units Are Good For Your Waistline

– Zack

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