The replacement museum in Golden Gate Park for the quake-damaged California Academy of Sciences opened as scheduled on Sept. 27. The building was designed by architect Renzo Piano with a 2.5-acre planted-roof exhibit that contains 1.7 million native plants and seven hills, reminiscent of San Francisco’s. The 410,000-sq-ft development, which contains a natural history museum, a planetarium, an aquarium, a rain forest and natural science research facilities, has been under way since 1999. Constructing the facility was challenging, thanks to its steep slopes and lack of repetition, says Webcor Builders.