Which states have the most LEED-certified building square footage per capita? The U.S. Green Building Council has crunched the numbers, and the results are in, with the District of Columbia leading the country in LEED-certified commercial and institutional green buildings (per capita, based on 2010 Census data). In 2011, our nation’s capital boasted more than 31 square feet of LEED-certified space per person, including the Treasury Building (how green can you get?), which happens to be the oldest LEED-certified project in the world. Of course, it helps that the District has a low residential population and all those government buildings: nearly a third of all LEED projects are government-owned or occupied LEED buildings, and the federal government alone owns and operates some 500,000 buildings. “But, hey! D.C. isn’t a state!” You say, with a disenfranchised gleam in your eye. Quite right. The top state is Colorado (2.74 square feet per capita and home to the LEED Platinum Casey Middle School in Boulder), followed closely by Illinois (2.69), Virginia (2.42), and Washington (2.18, did you know that Seattle’s Hard Rock Café is LEED Silver?). The Empire State cracks the top ten at 1.89, barely bested by California’s 1.92. According to the USGBC, there are roughly 44,000 commercial projects participating in LEED, comprising more than 8 billion square feet of construction space in all 50 states and 120 countries. Admire photos of LEED-certified buildings such as the undulating, Douglas Cardinal-designed National Museum of the American Indian, Discovery Channel HQ, and Denver’s Gold Museum of Contemporary Art on Flickr here.