When it came time for Major League Baseball's Washington Nationals to make plans to move out of 46-year-old RFK Stadium, progressive Kansas City, Missouri–based architecture firm HOK Sport and D.C.'s Devrouax + Purnell Architects were tapped to design a $611 million, 41,000-seat stadium with a focus on minimizing environmental impact as much as possible. Set to open March 30, the new Nationals Park, which is easily accessed via multiple bike, bus, and train routes—and possibly water taxis—will discourage car traffic with its scant 1,200 parking spaces, 5 percent of which will be reserved for carpoolers and hybrids. And that's just to start. Full LEED certification is imminent. According to HOK project manager Susan Klumpp, "it's the wave of the future." And, apparently, a home run.

1. COOL RUNNING: Compared with a traditional stadium of its size, the Nats' new home is a hopeless miser: Low-flow plumbing will reduce water consumption by 37 percent, saving 3.6 million gallons a year; fancy lighting will use 21 percent less power; the walls are highly thermally efficient; and a massive recycling initiative is in place.

2. BUILT TO PLEASE: Using low-VOC (volatile organic compound) adhesives, glues, and paints and local building materials reduced environmental impact and transportation costs and emissions. Roughly 5,500 tons of construction waste was recycled, and the structure may feature as much as 20 percent recycled content. And to lessen the strain on the nearby Anacostia and Potomac rivers, an intricate system made up of five 40-by-20-foot filters will catch organic debris, detergents, and the like in the wastewater.

3. SITE NOW SOUND: The stadium's 19 acres, once occupied by industrial facilities, was extremely polluted, but all contaminated soil was removed, and the groundwater is being treated. The site will now be liberally sprinkled with cherry trees—a grove will stand behind the outfield bleachers—and drought-resistant shrubs to eliminate the need for irrigation.