Signaling a shift from the traditional zoo approach, the National Zoo in DC asked a team, led by Allison Ewing, former Partner at William McDonough + Partners, to design a 35,000 SF visitors center. In support of the conservation focus of the zoo, the designers sought to incorporate sustainable strategies as learning tools. In addition to exhibit space, fans are connected directly to photovoltaic panels with velocities that change with the sun’s intensity. A large worm composting demonstration tank teaches visitors about how waste becomes food. The building’s energy requirements will be supplied by capturing methane from elephant dung for use as fuel.