Seattle North Transfer Station Receives IDEAS2 Award

Ignasius Seilie (center) and David Hornsby (left) of Integrated Design Engineers, Seattle, accept AISC’s 2018 IDEAS2 Award for excellence in building design using structural steel for Seattle’s North Transfer Station garbage transfer project from AISC’s Larry Flynn on September 27.

AISC presented a 2018 Innovative Design in Engineering and Architecture with Structural Steel (IDEAS2) Award to project team members of Seattle Public Utilities' new North Transfer Station Rebuild/Tipping and Transfer Building, as part of SteelDay last week.

“A great use of exposed steel throughout the facility, and an excellent long-span application,” commented Stephen Csernak, senior lecturer of civil engineering and undergraduate program coordinator at the Glenn Department of Civil Engineering at Clemson University, and the academic juror in the competition.

The new 67,000-sq.-ft transfer station, built to modernize the original 1960s facility, is topped with a 150-kW solar array and green space that covers 80% of the roof. Located on a tight, congested site in a well-to-do residential area, the building’s lower-level southwest corner had to be clear of columns and walls to allow truck entrance into the building after driving down the ramp from the street. In addition, the upper-level of the building had to be column-free for its full 200-ft span. A solution called the “floating corner” comprises a 50-ft cantilever truss and a 120-ft main transfer truss system that supports the weight of the entire building at its southwest corner.

To achieve the relatively low truss depth, the trichorded roof truss system uses the relatively new ASTM A1085 grade of hollow structural sections (HSS)—90 tons—which enabled the team to reduce the size of the bottom chord HSS and create a ductile trussed frame to resist seismic loading in the north-south direction.

The project’s team members include:

  • Owner: Seattle Public Utilities
  • Structural Engineers: Integrated Design Engineers, LLC, Seattle (entered the project in the competition); CDM Smith, Inc., Bellevue, Wash.
  • Architect: Mahlum, Seattle
  • General Contractor: Lydig Construction, Bellevue, Wash.
  • Steel Fabricator: Fought and Company, Inc. Tigard, Ore. (AISC member/AISC certified)
  • Steel Detailer: Steel Systems Engineering, Inc. Sherman Oaks, Calif. (AISC member)

The IDEAS2 award is the highest honor bestowed on building projects by the U.S. structural steel industry. And about this year’s winning transfer station, Charlie Carter, SE, PE, PhD, president of AISC, said, “It’s a savvy, innovative solution that adds use of the latest in new materials and integrates green technology to boot. A floating corner -- awesome!”

For more on all of this year's IDEAS2 award winners, see “2018 IDEAS2 Awards” in our May issue. The submission deadline for the 2019 competition has been extended to next Monday, October 8 at 11:59 p.m. CT. Enter your amazing steel-framed building projects at

(Photo at right: Integrated Design Engineers)