The nonprofit U.S. Green Building Council (USGBC) released its sixth annual ranking of U.S. states by the amount of space certified by its LEED rating system in 2015. This year’s list represents the highest average LEED-certified space per capita among the top 10 states since 2010 and includes six states that also appeared on the 2014 ranking. Illinois came in at the top spot for the third straight year, with 161 LEED certifications totaling 3.43 square feet of certified space per resident. Illinois and Colorado are the only two states to have made the list every year since 2010.

While Washington, D.C., is not included in the list due to its status as a federal territory, the district would have topped the list with 19.3 square feet per capita across 84 certified projects totaling 11.6 million square feet.

The chart below shows last year's list of states ranked by square footage certified per capita: