Portola Valley Town Center

Photo credit: © Cesar Rubio, courtesy of Siegel & Strain Architects

Materials & Resources

The project team made extensive use of reclaimed wood (26,000 board feet, about 25% of the wood used). Wood for interior paneling, ceiling slats, counters, and site carpentry was salvaged from buildings deconstructed on site. Salvaged Redwood siding was installed over a rainscreen that allows air to circulate behind the siding. Sunscreens are reclaimed Alaskan Yellow Cedar. All framing except for engineered joists is certified to Forest Stewardship Council standards. Local Eucalyptus was used for flooring in the community hall, and four Alder trees, cleared during construction, were used as columns in the new buildings.

Concrete, asphalt, and masonry materials from the existing buildings were ground up on site and used as backfill and sub base. Roughly 90% of the deconstructed buildings and 95% of new construction waste was diverted from landfills.

Reclaimed wood saved about 32 tons of carbon dioxide emissions —7 tons by eliminating kiln drying and 25 tons by keeping the wood out of landfills, according to the U.S. Environmental Protection Agency’s WARM calculator. The reuse of onsite and local materials saved 16 tons of carbon emissions associated with materials transportation. High-slag concrete (50% replacement of Portland cement) saved an estimated 55 tons of carbon emissions.

Design for Adaptability to Future Uses

Since the old building sat on the San Andreas Fault, the Town investigated the site to find an area suitable for building and chose the new location because it showed no signs of ground rupture for at least the past 5,000 years.

Flexible, wood-framed buildings on concrete slabs over a grid of grade beams were designed to keep the buildings standing after a major earthquake. The town hall houses the town’s emergency operations center and was designed to be operational after an earthquake.

The project team chose finishes for durability and low maintenance. Wood was used extensively—vertical redwood siding milled from salvaged old growth redwood was installed over a recycled plastic rain screen to allow the wood to dry from both sides and help reduce cupping. Wood sunscreens are made from salvaged Alaskan Yellow Cedar, a durable, rot-resistant wood that weathers to silvery grey.

The buildings were designed to accommodate a variety of uses. Several sizes of meeting rooms provide a place for the town’s volunteer committees to meet, and the large multipurpose room can be subdivided into two smaller spaces.

Green Strategies

• Building Deconstruction
  • Identify items to be reused from existing structure
• Design for Materials Use Reduction
  • Determine whether varying functions can be accommodated in shared spaces
• Greenhouse Gas Emissions from Manufacture
  • Replace up to 30% of the cement in concrete with flyash
• Salvaged Materials
  • Use salvaged wood for rough carpentry
  • Use salvaged wood for finish carpentry
• Materials and Wildlife Habitat
  • Use wood products from independently certified, well-managed forests for rough carpentry
• Transportation of Materials
  • Prefer materials that are sourced and manufactured within the local area

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Our thanks to the ENERGY STAR program of the U.S. Environmental Protection Agency, and to the U.S. Department of Energy, and to BuildingGreen, Inc. for hosting the submission and judging forms.

For more information about the AIA/COTE Top Ten Green Projects, contact AIA/COTE. For help on how to use this Web site, contact .