The California Academy of Sciences in San Francisco is celebrating 152 years of service and dedication to exploring, explaining and protecting the natural world. After suffering significant damage in the Loma Prieta earthquake of 1989 as well as the natural wear and tear from over 100 million visitors, the Academy needed a new home. Sustainability and conservation have long been a part of the Academy’s history. Consequently, the strategy behind the new construction was to create a new building that would not only hold powerful exhibitions, but serve as a tangible example of environmentally superior construction.
This new facility faced many challenges in achieving its desired “green” design moniker. Featuring an aquarium, a planetarium, and over 20 million scientific specimens, the building will encompass over 410,000 square feet of exhibition, educational and office space covering more than three acres. Pritzker Prize-winning architect, Renzo Piano of Renzo Piano Building Workshop (RPBW), Chong Partners, and ARUP Design - specialists in superior “green” design - were hired to meet the environmental goals and unique construction required for LEED-Platinum certification. Environmental construction specialists from Webcor Concrete served as General and Concrete Contractors.
Keeping the mission of the Academy in mind, it was necessary to pull “green” elements into all aspects of design and construction. The architectural team’s hallmark of the project is the 2.5 acre “live roof” with iconic rolling hills, serving as a thermal insulating layer for the building. It is projected to consume 30-35% less energy than required by code. Water efficiency was also addressed through the use of high-efficiency irrigation technology and reclaimed water from the City of San Francisco will be used to flush toilets reducing the use of wastewater by approximately 90%. Recycled building materials such as steel and recycled blue jeans were used to construct and insulate the walls and 50% of the wood in the new Academy was sustainably harvested and certified by the Forest Stewardship Council.
Because of the Academy’s unique design requirements, multiple critical applications of concrete were implemented to achieve the desired effect. For instance, “compactor” shelves were designed to hold collections of various scientific research materials, which ride on rails for ease of accessibility and require deflection criteria of L/720 only achievable with reinforced concrete. The aquarium tanks designed with complex geometries could only be cast in concrete. The primary architectural finish of the interior walls of the exhibit hall was built with as-cast architectural concrete. Concrete was also used as an integral part of the building’s mechanical system and also serves as a thermal massing element. As one of the more abundant building materials used for construction, it was important to choose mixes that were both environmentally friendly, high performing and durable.
Webcor approached several concrete suppliers to provide samples of their mixes. All mixes needed to leverage sustainable materials and meet an ultra low shrinkage requirement for the aquarium tanks, with the addition of a wall mix that could deliver an as-cast ‘A+’ architectural finish. San Francisco-based Central Concrete Supply was able to provide the best quality product at a competitive price to meet these goals.
Central Concrete Supply, Inc., an operating company of U.S. Concrete, provided approximately 35,000 cubic yards of concrete utilizing our environmentally friendly technology (EF Technology™) concrete mixes for the construction of the California Academy of Sciences project. These EF Technology mixes consisted of 50% Portland cement and 50% supplementary cementitious materials such as fly ash and slag - reclaimed by-products from iron mills and coal-fired industrial plants which would have ultimately ended up in landfills. By using EF Technology concrete mixes, 9.2 million pounds of greenhouse gas emissions (CO2) were prevented from entering the environment. Use of reclaimed by-products, fly ash and slag, as well as regionally extracted supplies of aggregates, in the production of the concrete greatly contributed to the building’s LEED rating.
Because of its commitment to “green” construction and design, the Academy was an honoured recipient of the Holcim Award for Sustainable Construction in North America in September 2007. Additionally, the Academy was awarded the Regional 2006 Environmental Award from the US Environmental Protection Agency (EPA).
The new Academy will optimize use of resources, minimize environmental impacts, and serve as an educational model by demonstrating how humans can live and work in environmentally-responsible ways. The new facility will integrate architecture and landscape, and help set a new standard for energy efficiency and environmentally responsible engineering systems in a public, architecturally distinguished building.
While many companies and technologies have converged to create the “green” building category, the Academy is one of the highest profile projects in the country to successfully leverage so many multiple elements in a single, large-scale development. Most notably, Central Concrete’s EF Technology product represents a significant leap forward in the use of environmentally superior concrete. Breaking ground in 2005, the new Academy is scheduled to open in Golden Gate Park in late 2008 and will serve as a positive example of engineering achievement and environmental sustainability for generations to come.
Concrete Contractor: Webcor Concrete
General Contractor: Webcor Builders
Architect: Renzo Piano Building Workshop
Engineer: ARUP Engineering – London, England
Owner: California Academy of Sciences
Number of Cubic Yards: 34,300 yds
Mix Specifications: Siteset, SiteFresh, and SCC
Pour Completion Date: February 2007
Project Completion Date: December 2008
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