The California Academy of Sciences is the largest public Platinum-rated building in the world and also the greenest museum in the world. Having been recently rebuilt by the architect Renzo Piano, it is one of the newest museums of natural history in the US, and one of the ten largest in the world. It is a masterpiece of architecture, located in Golden Gate Park in San Francisco, California, that combines the natural environment with hundreds of exhibits and thousands of unusual plants and animals. The Academy is a single structure, but contains multiple venues, including the aquarium, the planetarium, the natural history museum and the 4-story rainforest. In addition, there’s a 3D theater, a lecture hall, a Naturalist Center, two restaurants, an adjacent garden and aviary, a roof terrace, and an Academy store. It also houses the Academy science labs and administrative offices, including an extensive library and scientific archive consisting of more than 26 million specimens.

The building’s most recognized and talked about part is it’s green roof, which was designed to mimic the hills of San Francisco. The living roof has multiple uses. First, it provides an additional habitat for wildlife, second, it’s steep slopes serve as a natural ventilation and cooling system for the whole building, and thirdly, it retains 2 million gallons of rainwater, preventing 70% of the rainwater that falls on the roof from becoming runoff. The water that does run off the roof is collected in basement-level cisterns and reused for roof irrigation. No potable water is used to irrigate the living roof.