| Project Description | The new California Academy of Sciences building in Golden Gate Park is topped with a living roof. A new link in an ecological corridor for wildlife, this roof is planted with nine native California species that will not require artificial irrigation. The plants were grown at Rana Creek Nursery in Carmel Valley. Installation onto the roof took place from May to September, 2007. |
| Species Selection | Plant species were tested to ensure that they would survive on the rolling hills of the roof without artificial irrigation or fertilization. They were also selected to provide habitat for native wildlife. Over 30 species were tested on the roof of the old Academy before demolition; nine finalists were selected for inclusion. - Beach strawberries (Fragaria chiloensis) produce berries that attract a number of native birds.
- Self heal (Prunella vulgaris) bears large tubular flowers that are attractive to hummingbirds and bumble bees.
- Sea pink (Armeria maritime) produces pom-pom-like flowers that attract moths and butterflies.
- Stonecrop (Sedum spathulifolium) produces nectar for the Hairstreak butterfly and the threatened San Bruno elfin butterfly.
- Tidy tips (Layia platyglossa) attract parasitic wasps and pirate bugs that feed on pest insects.
- Miniature lupine (Lupinus bicolor) and California poppies (Eschscholzia californica) provide nectar for bees and butterflies.
- California plantain (Plantago erecta) hosts a variety of butterfly larvae, including the endangered Bay checkerspot butterfly.
- The bright yellow flowers produced by California goldfield plants (Lasthenia californica) attract a wide variety of beneficial native insects.
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| Coconut Husk Trays | 1.7 million individual plants have been planted into over 50,000 biodegradable coconut husk trays. These trays, which are composed of sustainable waste products from coconut plants in the Philippines, allow for easy roof installation and provide immediate root protection. They also support indigenous cooperative enterprises. |
| Roof Components | The living roof is composed of seven layers of material, designed to create insulation, prevent runoff, retain soil, allow for drainage, and promote healthy plant growth. From top to bottom, these layers are: - Biodegradable coconut husk trays containing three inches of soil and nine species of native California plants
- An additional three inches of soil
- An erosion control blanket designed to retain soil on the roof’s slopes, retain moisture mid-slope, and control pest plants
- A drainage layer to prevent to plants from rotting
- An insulation layer to stabilize internal building temperatures
- A waterproofing layer
- A concrete slab that follows the contours of the roof’s seven hills
Additionally, a grid of rock gabions helps hold soil in place and create access routes for roof maintenance. Operable skylights serve as vents and allow natural light to reach the living coral reef and rainforest below.
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| Roof Stats | - The living roof will decrease the urban heat island effect, staying an average of 40 degrees cooler than a standard roof
- It will absorb up to 3.6 million gallons of water per year (about 98% of all storm water), preventing runoff from carrying pollutants into the ecosystem
- It provides excellent insulation, keeping interior temperatures about 10 degrees cooler than a standard roof and reducing low frequency noise by 40 decibels
- Total square footage: 197,000 square feet (4.5 acres total roof space including solar panel canopy; 2.5 acres of planted material)
- Total number of plants: 1.7 million
- Total weight of soil and plants: 2.6 million pounds
- Total cost: $17.00 per square foot
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| Project Team | Architecture: Renzo Piano Building Workshop (Genoa, Italy); Stantec Architecture (formerly Chong Partners Architecture) (San Francisco, CA). Engineering and Sustainability Consulting: Arup. Living Roof: Rana Creek Living Architecture. Installation: Jensen Corporation. Landscape Architecture: SWA Group. General Contractor: Webcor Builders. |
| Media Contacts | Stephanie Stone
Tel: 415-379-5121
sstone@calacademy.org | Andrew Ng
Tel: 415-379-5123
ang@calacademy.org |
