Preliminary research suggests that energy efficient buildings commanded higher occupancy and rental rates while sales prices were as much as 30 percent higher per square foot. To boot, operating expenses were lower.

Norm Miller, a professor at the University of San Diego, and Jay Spivey and Andy Florance, the research director and CEO of CoStar, a real estate data research company, wrote "Does Green Pay Off?" late last month.

The trio compared Energy Star-rated buildings against their conventional counterparts. The authors note that the benefits of green buildings may not yet be visible in the data since tenants might require proof that the cost of investment will help them save money. Operating costs and a boost in productivity, however, translate to longer-term savings.

Without a large data sample comparing LEED-certified and conventional buildings, the authors used information from the U.S. Green Building Council to compare the cost differential between green and conventional buildings. Previous surveys suggest that LEED-certified buildings can cost between 1 percent and 10 percent to build, depending on the certification type. LEED-certification, however, doesn't always equate ENERGY STAR status.

Green building barriers include a lack of planning, which can cut down on costs, and education. The authors suggest that better information, transparency and industry standards are needed.

"We need such a rating system for energy consumption along with systems that provide information on building adaptability and resource impact," the authors said. "Some day we may see large property owners with green self-sustaining solar-powered mixed use developments selling off carbon credits to others."

The report identified the top green building metro areas as Los Angeles, Houston, Washington, D.C., New York City and San Francisco. The top states were California, Texas, New York, Minnesota and Colorado.