In 2007, the Portland Regional Multiple Listing Service (“RMLS”) began tracking sales of homes with a green certification such as Energy Star, LEED for Homes, or Earth Advantage New Homes. The Earth Advantage Institute, an Oregon-based non-profit doing work in the green building sector, annually reviews this information in order to glean home valuation trends.

Specifically, Earth Advantage found that existing homes with a green certification sold for 30% more than homes without such a certification. Earth Advantage also found that new homes with a green certification sold for 8% more than new homes without a certification.

The research is based on sales between May 1, 2010 and April 30, 2011 in Multnomah, Clackamas, Columbia, and Washington Counties in Oregon, and Clark County in Washington. While there are differences in the various counties, the data supports the notion that new and existing homes with a green certification have higher sale values.

In addition, Earth Advantage found that of 2,237 new homes sold in the last year in the Portland RMLS area, 408 of those homes were certified to some green standard.  Thus, the Portland area is seeing about 18-20% market share of certified new homes and these homes all have a sizable price premium.

There is one big thing to keep in mind.  The amounts are based on averages of all homes in the county, not comparable properties, and a larger number of higher priced green homes may raise the averages.  But as a point of reference, the research indicates that homes with certification yield a price premium when sold.

[+] Read the report summary by Earth Advantage Institute.

Credits: Earth Advantage Institute (tables).