Building Honors Site's History as an Aggregate Mine with Extensive Use of Concrete
This building sits on a 900+ acre site, much of which has been extensively mined for gravel for over 100 years, resulting in a barren landscape. Historically the site is known as the Steilacoom Gravel Pit. As the first major building constructed under “Reclaiming Our Resources”, the county's 50-year master plan for the site, it sets the tone for future development.
The project’s driving concepts call for a more humane work environment, introduction of natural light, interior vegetation, and views to the exterior. It attempts to make people aware of being part of a greater regional context by developing the “Mt. Rainier” axis through the site. Space planning follows a European office model: No desk is more than 30 feet to a window. Extensive daylighting studies led to the use of baffles in the skylights, a large western overhang, and exterior sunscreens on the east façade. A raised-floor air distribution system reduces the size and energy consumption of the mechanical system, improves indoor air quality, provides for future flexibility, and gives individuals direct control of their immediate environment. Nighttime flushing lowers the temperature of the concrete structure by several degrees, resulting in “free” cooling at the beginning of the day.
The material originating from the Steilacoom Gravel Pit is well known among structural engineers as being some of the best concrete aggregate in the world. This fact has resulted in the design team’s unanimous decision to use concrete extensively throughout the project, creating a symbolic tie to the historical use of the site. The local nature of the project aided in the design team and owner’s commitment to making it a sustainable project as well.
The variety of concrete material used in the project includes:
- Primary structural system: cast-in-place concrete sheer walls, columns and beams;
- 2nd Floor: concrete planks;
- Roof framing: concrete planks;
- Interpretive Exhibit Program: Shotcrete site walls (designed to show off the matrix and stratification of gravel found on site); and
- Staggered formed office pods and conference rooms: reinforced concrete provided the structural characteristics and span-to-depth ratios that were critical to creating gravity and lateral structure. The design also gave the office interior more light and made it virtually column free.
The raised floor air distribution system reduces the size and energy consumption of the mechanical system, improves Indoor Air Quality, provides for future flexibility and gives individuals direct control of their immediate environment. Nighttime flushing moves cool night several degrees. This concept, called Fabric Energy Storage, takes advantage of the thermal mass of the concrete structure and provides “free” cooling at the beginning of the day, resulting in significant energy savings over the lifespan of the building.
Owned and occupied: Pierce County Public Works and Utilities, local government
Architect: Miller/Hull Architects, Seatttle, Washington
Structural Engineer: AHBL Site Planner, Tacoma, Washington
Interior Design: Arai/Jackson Architects & Planners, Seattle, Washington
Mechanical Engineer: AE Associates, Greeley, Colorado
Landscape Architect: Bruce Dees and Associates, Tacoma, Washington
Electrical Engineer: J Omega, Kenilworth, United Kingdom
Civil Engineer: SvR Design Co., Seattle, Washington
Contractor: Wick Constructors, Inc., Bellevue, Washington
Construction Manager: Olympic Associates, Seattle, Washington