And the U.S. city with the highest percentage of green commercial space is. . .Minneapolis!

Actually, the Twin Cities.

According to a new study called the 2014 Green Building Adoption Index by the real estate firm CBRE Group Inc. and Maastrict University in the Netherlands, the Twin Cities' ranking is "remarkable." All told, 30 U.S. cities were surveyed in the report.

Seventy-seven percent of the commercial real estate space in the Twin Cities is certified as green, the study states. We're followed by San Francisco (67.2 percent); Chicago (62.1 percent); Houston (54.8 percent); and Atlanta (54.1 percent).

"We have all seen the rapid growth in the number of green-certified buildings in the markets in which we work; however, we were quite surprised to see how large the numbers actually are. Green is absolutely the new norm," said Dave Pogue, CBRE's Global Director of Corporate Responsibility, in a statement.

The study notes that 135 buildings in Minneapolis are certified green, representing more than 152 million square feet of office space. That means 29.7 percent of the buildings here are green, better than 26.6 percent in Atlanta and 24.4 percent in Manhattan.

Put simply, more than three-quarters of all office space in the Twin Cities is green.

Minneapolis also holds the leading position in Energy Star label categories, including 22.9 percent of buildings and 62.8 percent of square footage, according to the report. And the market leads in LEED certification categories, with 12.1 percent of buildings and 39.4 percent of space certified. Both rankings are more than double the national average.

Part of the reason for Minneapolis' high ranking is that Minnesota law includings a Commercial Building Rating and Disclosure ordinance requiring commercial buildings larger than 50,000 square feet to use Energy Star tor track energy and water use. The information is disclosed to the government and posted on a public website.

The other part is cultural. "Sustainability is clearly integrated into the fabric and dynamics of the Minneapolis real estate market, driven by solid demand from corporate tenants," the report says.

Other fun facts: The first LEED-certified building was the Karges-Faulconbridge Office building in Roseville, which earned LEED gold for an existing building in November 2004.

In addition, 7601 Penn Av. S.(Best Buy headquarters in Richfield) earned an Energy Star certification 10 times and is LEED-Gold certified.