Seattle North Transfer Station Wins National Steel Design Award

September 17, 2018

(Chicago, IL) – Seattle Public Utilities' new North Transfer Station Rebuild, Tipping and Transfer Building has earned national recognition in the 2018 Innovative Design in Engineering and Architecture with Structural Steel awards program (IDEAS2). In honor of this achievement, members of the project team will be presented with awards from the American Institute of Steel Construction (AISC) during a ceremony to take place at the building on Thursday, September 27, at 2 p.m. The awards presentation coincides with the 10th annual SteelDay (Friday, September 28), a day of recognition and celebration of the value and expertise the U.S. structural steel industry brings to our country’s building and bridge projects (for more information and to find an event near you, visit

“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 12 IDEAS2 winners for 2018 were chosen from nearly 100 submissions received from architectural and engineering and other project team member firms throughout the U.S. Each submission is reviewed and award winners are selected by a nationally recognized panel of design and construction industry professionals.

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!”

Members of the media may request high-resolution images of the project by contacting AISC’s Tasha O’Berski at 312.670.5439 or For more information about the IDEAS2 awards and to view all of this year’s winners, please visit Entries for the 2019 competition are being accepted until SteelDay, September 28, 2018. 

(Photo: Integrated Design Engineers)


For more information contact:

Dani Friedland
Marketing Communications Strategist

American Institute of Steel Construction

The American Institute of Steel Construction, headquartered in Chicago, is a non-partisan, not-for-profit technical institute and trade association established in 1921 to serve the structural steel design community and construction industry. AISC's mission is to make structural steel the material of choice by being the leader in structural steel-related technical and market-building activities, including: specification and code development, research, education, technical assistance, quality certification, standardization, market development, and advocacy. AISC has a long tradition of service to the steel construction industry of providing timely and reliable information. 

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