When San Francisco’s 150-year-old California Academy of Sciences reopens at the end of September 2008, it will be the largest public building to receive a LEED Platinum certification, making the museum a likely candidate for the greenest museum in the world.

Located within picturesque Golden Gate Park, the California Academy of Sciences is a vanguard in green design. 60,000 photovoltaic cells cover the building’s exterior, providing 10% of its energy. But these solar cells aren’t the crown jewel of the museum’s green design--the 197,000-square foot living rooftop is.

The curved roof of the museum features 1.7 million native plants. The vegetation is anchored to the undulating slopes with 50,000 porous and biodegradable trays, made from tree sap and coconut husks and laced together like patchwork to let the plants’ roots develop. The living roof will transform carbon dioxide into oxygen, absorb rainwater, and perhaps best of all, keep the interior of the building about ten degrees cooler than other similarly-sized edifices.

Between the cooling effects of the living roof and the excellent wall insulation provided courtesy of batting that is made from recycled blue jeans, the museum won’t need air conditioning. To keep the building warm during the chilly Bay Area winter, a radiant heating system has been installed in the museum’s floors. Tubes carrying hot water are embedded in the building’s concrete floors, warming the floors themselves and reducing the building’s energy need by 10%.

As you might expect by now, every aspect of the museum’s design has sustainability and energy-saving practices in mind. Floor-to-ceiling glass walls provide 90% of the building’s internal offices with natural light. Skylights will open and close automatically to provide light to the museum’s rainforest and aquarium and let hot air escape the building. Louvers will draw in cooler air from the skylights to help cool the lower floors.

But what about the museum’s contents? While the building’s eco-friendly design is a sure draw for environmentalists around the world, it’s the museum’s attractions and exhibits that will bring the crowds. There is an enormous planetarium (one of the world’s largest), an aquarium that features a coral reef system straight from the Philippines, a flooded Amazon rainforest complete with native plants and animals from around the world, two restaurants that focus on fresh and healthy food, an observation terrace, and a special exhibit on the California Coast.