Seminar II, The Evergreen State College

Photo credit: Lara Swimmer

Site Description

Prior to groundbreaking, local Native American groups held a ceremony to bless the site. They also collected bark and branches from sacred cedar trees for use in traditional carving and basket weaving.

To safeguard the site’s forest ecology, Seminar II is broken into five pieces and fingered into the landscape. Overstory, understory, and ground planting features a mix of native species organized according to their natural settings and replaces the areas disturbed by construction. Stands of fir and cedar trees located between clusters were protected during construction. The ecological restoration was so successful that raccoon and deer were sighted again within a year of occupancy.

Given the site’s location within the Thornton Creek watershed, which is habitat to the endangered Pacific salmon, the project team strove for no net increase in stormwater runoff into this critical area. Working with the jurisdiction, the team created a computer model of the entire watershed to study the impacts of two design strategies: green roofs and stormwater detention. The result was the application of 20,443 ft2 (51% of the footprint area) of vegetated roof planted with a variety of sedums, wildflowers, and grasses. This is the largest green roof in the Pacific Northwest.

As the campus receives more than 51 inches of rain per year, a major goal of the design committee was to celebrate this abundance in the building’s design. The design of the stormwater detention system was an opportunity to reveal this abundance. Very little of the stormwater is piped underground; most runs in surface runnels through a centralized landscape made of rocks and plants, culminating in an open rock garden that serves as a detention pond. The detention, significantly reduced in size by the roof performance, saved $144,000 and offset the additional roof-assembly costs.

• Lot size: 165,492 ft2
• Previously undeveloped land

Water Conservation and Use

The reduction of water use in the project was discussed at great length throughout the eco-charrette and design process. Various initiatives, including composting toilets and greywater reuse systems, were explored and exhaustively researched. In the end, obstacles were too great and the payback too small to justify large-scale experiments in this project. Instead, more conventional conservation measures such as waterfree urinals, automatic faucets, and low-flow toilets were incorporated to achieve a potable water savings of 25%.

The landscaping features 98% native species, which are planted according to sun and moisture requirements and will require no irrigation after the initial establishment period. No new lawn areas were created. Stormwater channeled through the site’s central garden supports a post-glacial landscape with a rich mixture of plants.

Water Data

• Indoor potable water use: 723,000 gal/yr (2,740,000 liters/yr)
• Outdoor potable water use: 0 gal/yr (0 liters/yr)
• Total potable water use: 723,000 gal/yr (2,740,000 liters/yr)
• Potable water use per unit area: 4.3 gal/sq ft (175 liters/sq meter)

Green Strategies

• Development Impacts
  • Cluster buildings to preserve open space and protect habitat
• Waterless Fixtures
  • Specify waterless urinals
• Runoff Reduction
  • Design a green roof system
• Landscape Plantings
  • Landscape with indigenous vegetation
• Low-Water-Use Fixtures
  • Use low-flow toilets
  • Use automatic faucet controls for lavatories
• Demand for Irrigation
  • Select plants for drought tolerance
  • Arrange plantings in groups according to water needs
• Integration with Site Resources
  • Celebrate and enhance existing landscape features
• Site Planning
  • Site buildings so as to help occupants celebrate the natural beauty

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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 .