CHICAGO—When CBRE Group, Inc. first launched a research project to study energy efficiency in US buildings, company officials expected to find that green buildings were a bicoastal phenomenon. But although San Francisco did rank second in the amount of commercial office space considered “green,” it was Minneapolis and Chicago which placed first and third, respectively, among the 30 markets studied for the 2015 Green Building Adoption Index, a joint project of CBRE, Maastricht University and the US Green Building Council.

The index charts the growth of ENERGY STAR- and LEED-certified space in US office markets. Although Chicago saw a reduction in the total number of certified buildings–287, down from 294 last year–the percentage of all square footage in those buildings increased to 63.4%. And the percentage of square footage in LEED-certified buildings was 38.5%, up nearly 7%. CBRE officials say this is most likely the result of ENERGY STAR–labeled buildings also achieving LEED certification.

“This is a first-tier market with a lot of high-profile owners and green-certified buildings also tend to be a big city phenomenon,” David Pogue, CBRE's global director of corporate responsibility, told GlobeSt.com.