Having a "green," or environmentally friendly, home can add about 9 percent to the sale price in California, according to a study released Thursday by researchers at UCLA and UC Berkeley.
The study, titled "The Value of Green Labels in the California Housing Market," examined data on the 1.6 million single-family homes sold between 2007 and 2012. About 4,300 of them were certified with green home labels from Energy Star, GreenPoint Rated or LEED for Homes.
Based on an average home price of $400,000, homes with a green label sold for an average of $34,800 than comparable homes without the energy-efficiency designation, according to the study.
"In certain regions of the state, we observed a phenomenon we've termed the 'Prius effect' -- a positive correlation between the value of green home labels and environmental ideology, as measured by the rate of hybrid registrations," said Nils Kok, visiting professor at UC Berkeley and one of the lead researchers.
"In communities with strong environmental values, residents may see green homes as a point of pride or status symbol."
Researchers said the study was the first large-scale independent economic analysis of the value of green home labels in California.
According to a separate study by Energy Upgrade California LA, the value of a home in Whittier owned by Colleen Kienzle increased from $720,000 to $765,000 -- 6 percent -- when it underwent environmentally friendly upgrades such as weather stripping, insulation, air-sealing, improved shower valves and an upgraded pool pump.
In addition to the price increase, the home also experienced a $2,237 annual drop in energy costs, according to the study.
A Los Angeles home owned by Lisa Brown saw a 5.5 percent increase in value after "green" upgrades were made.
"I was excited to upgrade my house because the potential for savings was great, coupled with the fact that upgrades will make my house more comfortable," Brown said. "Most importantly, I can now reduce my carbon footprint."
According to the researchers, the estimated average $34,800 price premium for green-labeled homes in California is significantly greater than the price increase associated with other typical home improvements made prior to sale.
The researchers cited a 2012 survey by HomeGain, which showed staged homes sold for an average $2,144 more than non-staged homes and upgrades to the kitchen and bathroom resulted in an increase in sale price by $3,254.
The study also found that the price premium associated with green labels varies considerably from region to region throughout the state and is highest in the hottest climates.
The researchers said the benefits of green homes include lower operational costs, high quality construction, more comfortable and stable indoor temperatures and healthier indoor air quality.
Energy Upgrade California LA is offering rebates of up to $8,000 to Los Angeles County homeowners making energy upgrades and $2,000 for qualifying for a green label.