Text description provided by the architects. The Center for Urban Waters was envisioned by the City of Tacoma to be a beacon on the water and an example of using building and site sustainable strategies for all future projects in the City. The 51,000 sf, three-story building functions as a shared research facility for City of Tacoma and University of Washington Tacoma to receive and analyze water samples from the waterways of Tacoma and surrounding areas. The building program is comprised of laboratories, offices, conference rooms, a lunch room, an exhibit center, a customer service center at the lobby entrance, and related building services including a mooring facility on the Thea Foss Waterway. The building is sited to optimize views across the waterway toward the city and views toward Mt. Rainier, to maximize public open space, and to provide access to the shoreline esplanade and to on-site parking.
Sustainable Strategies: The building is designed to achieve LEED Platinum certification, and some of the sustainability strategies include natural ventilation of the office environments, sun-shading of the south and west facades, vegetated roofs, storm water collection, and water reuse. Materials selected for the building’s interior and exterior were selected based on quantity of recycled content, where the product was manufactured, amount of VOCs (volatile organic compounds) in the product, and whether the product was certified (as in the case of wood products).
A highly recycled aluminum plate rainscreen and corrugated metal siding are used on 3 sides, and a glazed curtain wall with fixed horizontal shades on the south. The design capitalizes on the City of Tacoma’s desire to reuse materials from the local landfill by recycling granite curbs into benches on site.
Heavy timbers were milled and reused for the ceiling and wall panels in the lobby and main conference room. Tree snags along the waterway and public esplanade provide staging, feeding, and perching for birds of prey, such as osprey, bald eagles and hawks. Responsible waste management before and during construction was also a factor in achieving this certification.
The water testing planned for the building labs required a detailed understanding of the material content for finishes used in these spaces. Interior finishes and building materials in the Metals Analysis and Metals Clean Rooms (trace metals testing labs) were designed to avoid any exposed metal surfaces. The Organics Clean room and City of Tacoma labs tested for phthalates and other elements commonly found in fire protection products and building finishes. The city rigorously tested each of the materials selected for floors, ceilings and counters in these labs.
Water Reduction: The majority of the site’s surfaces are permeable to reduce storm water runoff. These include rain gardens, 2 green roof areas, porous paving and plantings. A portion of the green roof area and the site rain gardens absorbs and treats rain water to reduce the quantity of site water runoff.
In addition to the storm water collected from the green roofs that has seasonal peaks, the clean reject water from the lab’s production of reverse osmosis water provides a constant year-round water supply for the building and site needs. This water is collected and stored on the site’s two 36,000 gallon water storage tanks. The site collects and stores excess reverse osmosis water from the labs and annual precipitation from a portion of the green roof. This water is then reused for toilet flushing and all of the landscape irrigation. Based on the potable water consumption per year, this system in conjunction with water conserving fixtures saves 400,000 gallons of water each year.
Energy strategies: The Center for Urban Waters utilizes several strategies to reduce its energy needs. Exterior sunshades and high performance glazing reduce unwanted heat gain. Natural ventilation cooling and a ground source heat pump that charges radiant floor slabs reduce the energy required for heating and cooling. The lighting controls and a narrow floor plate provide a well daylit space that requires minimal energy for lighting. Utilizing a field of 72 closed loop ground source wells, a system of heat pumps serving radiant floor slabs provides heating and cooling for the entire building. Low flow Variable air volume fume hoods boost the energy efficiency of the fume hood intensive labs. Through these strategies, the building overall energy usage is 38% more efficient than ASHRA 90.1 2004 standards for energy efficiency.