Press Release

Stephanie Stone (415) 379-5121
sstone@calacademy.org

Andrew Ng (415) 379-5123

Project Description

The new California Academy of Sciences building in Golden Gate Park will be topped with a living roof. A new link in an ecological corridor for wildlife, this roof will be 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 Academy roof began on May 25.
 

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 maritima) 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.
     
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, will allow for easy roof installation and provide immediate root protection. They also support indigenous cooperative enterprises.
 
Better for Butterflies Many butterfly species will benefit from the new roof, including the endangered Bay checkerspot butterfly, which once inhabited many regions around the San Francisco Bay. Today, only half a dozen colonies of this critically endangered butterfly remain, largely due to habitat loss. The new Academy roof will create excellent habitat for this species, since it will provide both a host plant for the larvae and a nectar source for the adults. California plantain (Plantago erecta) is the primary host plant for Bay checkerspot larvae, and California goldfield (Lasthenia californica) and Tidy-tips (Layia platyglossa) both provide nectar for the adults.
 
Roof Components

The living roof will be 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 will help hold soil in place and create access routes for roof maintenance. Operable skylights will serve as vents and allow natural light to reach the living coral reef and rainforest below.
 

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 will provide 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.
     
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. 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

 


The California Academy of Sciences is home to Steinhart Aquarium, Morrison Planetarium and the Kimball Natural History Museum. The Academy is in the midst of an extensive rebuilding project in Golden Gate Park. Pritzker prize-winning architect Renzo Piano is designing the new Academy, which is scheduled to open on September 27, 2008. www.calacademy.org (415) 379-8000.

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