u201cHouston office building managers and owners have designed and retrofitted facilities to be well-suited for the age of energy efficiency,u201d Taylor says.

HOUSTON–According to the 2014 Green Building Adoption Index, Houston ranks fourth in the nation of the cities with the highest percentage of green commercial space. The index is a joint project between CBRE Group Inc. and Maastricht University. The study shows a significant increase in green space from 2005.

Houston has 54.8% of its commercial real estate space certified as green through either the EPA Energy Star label or the USGBC LEED certification, or both. The oil and gas companies headquartered in the area have helped lead this movement. Another factor is the 2004 mandate, Resolution 2004-15, which requires city-owned buildings larger than 10,000 square feet to pursue LEED standards.

“Houston office building managers and owners have designed and retrofitted facilities to be well-suited for the age of energy efficiency,” says Mark Taylor, senior managing director of CBRE’s Houston office. “Since Houston is the energy capital of the world, sustainability is paramount to all aspects of our economy. This is evident in the way real estate has been consistently managed on a local level, and we will certainly see this trend continue in the years to come.”

Minneapolis ranks first with 77% of its commercial real estate space certified as green. San Francisco comes in second (67.2%) and Chicago third (62.1%). Other Southwest cities that made the list include Dallas/Fort Worth (32.7%) and Phoenix (28%).

“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,” says Dave Pogue, CBRE’s global director of corporate responsibility, in a statement.

The index is the first project conducted by CBRE’s Real Green Research Challenge. RGRC, which launched in September 2012, is a $1 million commitment to fund sustainability research and innovation within the industry.

“This is the first study to quantify the relevance of green building practices in the commercial real estate market,” said Nils Kok, associate professor in Finance and Real Estate at Maastricht University. “While we all know examples of LEED-certified buildings, the results presented here are facts based on a robust methodology, not anecdotal evidence. The evidence shows that green has become mainstream in all major US cities.”