(How does your city stack up against the Top 10? Scroll down and comment!)

WASHINGTON, DC-Washington, DC once again heads the USGBC's list of top performers in LEED certification. The locally based group's annual ranking shows that the nation's capital certified 110 projects last year, for a total of 22.2 million square feet.

While other states logged higher square feet, it is the per capital square footage of LEED certifications that drives the ranking, and DC logged 36.97 square feet in this category.

This was far and away superior to any of the other ranking nine. Virginia, which came in second, could muster only 3.7 square feet per capita out of its 170 certifications filed. Colorado came in third with 2.1 square feet (99 projects), followed by Massachusetts' 2.05 (106 projects) and Illinois with 1.9 square feet per capita in 156 projects. Maryland, New York, Washington, California, Texas and Nevada rounded out the top 10.

GlobeSt reached out to David Pogue, CBRE's global sustainability director, to find out what the ranking means for green buildings' expansion in 2013. He told us that "the continued exponential growth of the LEED for Existing Buildings rating system accentuates the fact that commercial property owners are proponents of long-term sustainable operations and environmental best practices."

According to the USGBC, the per capita ranking was based on 2010 census data. “Securing a spot on this list is a remarkable achievement for everyone involved in the green building movement in the states,” says Rick Fedrizzi, the association's president, CEO and founding chair. “From architects and designers to local chapter advocates, their collective efforts have brought sustainable building design and use to the forefront of the national discussion on the environment, and I applaud their efforts to create a healthier present and future for the people of their states.”

The association also provided a list of some of the significant projects that made the cut in 2012. They included: the US Mint Building in Washington, DC, National Football League corporate headquarters in New York City; the Dallas Convention Center Hotel; and the Center for Urban Waters in Tacoma, WA.