California Academy of Sciences Showcases Sustainability

If you track green building developments, you may already know that the new California Academy of Sciences in San Francisco will have the largest and most complex living roof in the world–two acres planted with nine kinds of native flora (1.7 million seedlings), along with seven structural domes, glass skylights, and a photovoltaic canopy. But you might not know that the commitment to innovation and sustainability seen in the roof design permeates every aspect of the Academy's building and programs.

Located in Golden Gate Park, across from the dazzling new de Young Museum, the Academy is the oldest scientific institution in the western United States and the only place an aquarium, a planetarium, and a natural history museum share a roof, green or otherwise. With 410,000 square feet and 18 million specimens, it is one of the largest natural history museums in the world.

More than a decade of planning and fund-raising led to the selection of the project team in 2001, and they've been sprinting ever since. Construction started in September 2005 and is slated for completion in late 2007. Crews are busy at the job site 20 hours out of every 24, and the 150 workers onsite are quietly intense as they go about their tasks. The stakes are high: At $280 million for the building and another $100 million for the exhibits, the project is the largest and most expensive cultural project in San Francisco history. Its new home will help the Academy expand its mission to explore, explain, and protect the natural world.

Exploring, Explaining, and Protecting the Environment

Exploring is the stock-in-trade of research scientists in eight distinct disciplines, from anthropology to invertebrate zoology. Their labs will be visible to the public for the first time when the new building opens in late 2008. Explaining is what the Academy does best, with classic tools such as signs, dioramas, and tours, along with the modern additions of podcasts and online videos. And as for protecting the environment, it's embedded in everything the Academy does—its building, exhibits, research, and policies.

Conceived by Renzo Piano Building Workshop of Genoa, Italy, in collaboration with San Francisco-based Chong Partners Architecture, the building's central piazza and four quadrants encompass a wide array of activities and programs, including labs, offices, a café, auditorium, classrooms, millions of specimens (living and preserved), and public exhibits. By moving some of the functions underground, the designers reduced both the footprint and the height of the building, restoring more than an acre of parkland and sight lines to the hills beyond. Operable skylights in the domes and a computer-controlled, naturally ventilated facade will allow hot air to escape and draw cool air through from below, making the structure itself part of the HVAC system.

"This project is challenging from an architectural perspective," says Pamela Brandon, the project manager from Arup, the global engineering firm. "But the engineering is even more extreme." Brandon leads the team of more than 20 engineers responsible for the structural, mechanical, electrical, plumbing, lighting, and facade systems. The large twin spherical interior domes, skylight-punctured living roof, and vast open piazza are just a few of Piano's features that push the limits of traditional engineering design. The systems and structures needed to keep visitors and occupants safe, comfortable, and productive are more challenging than usual when the latter include scientists as well as the fish, amphibians, birds, and invertebrates they study.

Achieving LEED Platinum—The Highest Standard in Green Building

Another dimension of the design is its targeted LEED® Platinum rating, representing the highest standard in green building awarded by the U.S. Green Building Council. Arup is leading the sustainability effort across the 10 disciplinary teams involved in the project, drawing on the firm's own experience and commitment to the environment. Founded 60 years ago in London by Sir Ove Arup, the company invests heavily in research and tools that support sustainable design, such as its Sustainable Project Appraisal Routine (SPeAR). It's a scorecard that assesses the social, economic, and environmental impact of a project across 20 different dimensions, allows comparison between options, and monitors performance over time.

Arup also uses commercially available tools such as Autodesk's advanced 3D software to predict the performance of its designs, compare alternative options, and anticipate their impact on the environment—all during design development. On the Academy project, Arup used the 3D tools in AutoCAD® software to help the structural engineers model the geometry for the roof's structure. (The firm now uses even more advanced products, Autodesk® Revit® Structure and Autodesk® Building Systems.) The living roof was designed to absorb thousands of gallons of rainwater before sending the excess flow to a recharge chamber and then to the aquifer, so structural experts built models to ensure that the web-like steel frame could bear the weight of the water-soaked soil. The domes above the planetarium, the rainforest, and the piazza all have skylights to bring natural light into the core of the cavernous building, so lighting engineers used simulations to optimize their placement. The mechanical engineers validated the amount of air exchange needed for the innovative ventilation system (part natural, part mechanical). Electrical designers ran simulations to ensure that energy usage would be 20 percent below California's stringent energy efficiency standards. In every case, the models allowed the experts to quickly test and fine-tune their designs.

Mimicking Nature in Exhibit Designs

Trying to mimic nature to enable living things to thrive inside a building is hard work. Each exhibit is an ecosystem that mirrors the natural environment as closely as possible. "We're trying to produce healthy, real conditions for them. It's part of the educational process," says Jean Rogers, a sustainability consultant at Arup.

For example, both the 25-foot-tall living coral reef (the world's deepest) and the living rainforest need immense amounts of intensely bright light if they are to thrive, but also need darkness each day. With only 24 hours in the day, it's a challenge to meet these requirements and also illuminate the exhibits during visiting hours so the public can safely see and enjoy them. Add the need to accommodate seasonal changes in daylight, and you can see why it's all monitored and managed by computers.

Providing the right kind of saltwater and freshwater habitats for thousands of fish is equally complex. Saltwater for the aquariums will be piped in from the Pacific Ocean. Nitrate wastes will be purified with natural systems, ensuring that aquarium water can be recycled. Enormous tanks, pumps, and filters will create a sophisticated life support system, with extensive emergency backup. Specially designed acrylic panels must be beautiful enough to entice the viewer up close, yet strong enough to withstand the 1,600 pounds per cubic foot of pressure created by a 212,000-gallon tank.

From its organic restaurant menu and composting program, to the use of nontoxic cleaners and natural pest management practices, the Academy's new building will help it continue to fulfill its mission of educating the public and protecting nature for decades to come.