"Built Green'' homes grew in value in last two years

Certified "green" Seattle-area homes appreciated in value in 2007 and 2008, while comparable uncertified homes either depreciated or appreciated less, a new study says.

The average sale price of town houses within Seattle built after 2003 and certified as "Built Green" was up 1 percent in 2007 and 8 percent during the first eight months of 2008, according to the report. In contrast, it says, the average sale price of Seattle town houses of similar vintage without the certification slipped 5 percent in 2007 and 4 percent through August 2008.

"Built Green" is a program of the Master Builders Association of King and Snohomish Counties that provides certification for new homes with environmentally friendly features. The program commissioned the study, completed earlier this year by economic-consulting firm Gardner Johnson.

The report also examines how "Built Green" single-family houses built this decade on the Eastside have fared in comparison with uncertified houses.

The median sale price of certified homes increased 13 percent in 2007 and 2 percent through August 2008, the study says, while uncertified houses appreciated 9 percent in 2007 before dropping 2 percent during the first two-thirds of 2008.

Some builders maintain buyers won't pay more for green construction, said Aaron Adelstein, Built Green's executive director.

"We in the green-building movement have always felt that to be wrong," he said. Now we have some data that supports that."

But study author Sterling Hamilton said it's too soon to say whether "Built Green" certification caused the differences in appreciation the report found. Other variables may come into play.

For instance, Hamilton said, many of the certified Eastside houses in the study are in "master-planned" communities such as Issaquah Highlands, while most of the uncertified homes are not.

More sophisticated research is needed to nail down green certification's impact, he said.

Built Green is looking for grants to fund a more detailed study, Adelstein said.

The program has certified more than 13,000 homes in King and Snohomish counties since its launch in 1999.

Eric Pryne: 206-464-2231 or epryne@seattletimes.com