USACE Federal Center South Building Wins National Architecture and Engineering Award


September 2, 2014 from American Institute of Steel Construction

Chicago, IL – September 2, 2014 – (RealEstateRama) — The U.S. Army Corps of Engineers Federal Center South Building 1202 in Seattle has earned national recognition in the 2014 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 at the building on Thursday, September 4, at 11 a.m.

Conducted annually by AISC, the IDEAS2 awards recognize outstanding achievement in engineering and architecture on structural steel projects across the country. The IDEAS2 award is the highest, most prestigious honor bestowed on building projects by the structural steel industry in the U.S. and recognizes the importance of teamwork, coordination and collaboration in fostering successful construction projects.

The building’s project team members include:

Owner: U.S. General Services Administration, Northwest/Arctic Region
Architect: ZGF Architects LLP, Seattle
Structural Engineer: KPFF Consulting Engineers, Seattle
General Contractor: Sellen Construction, Seattle

The U.S. Army Corps of Engineers Federal Center South Building 1202 is a National award winner in the category of projects $15 Million to $75 Million, making it one of only three projects around the country to receive the National honor. Each year, the IDEAS2 awards honor National and Merit award winners in three categories, based on constructed value: projects less than $15 million; projects $15 million to $75 million; and projects greater than $75 million. Each project is judged on its use of structural steel from both an architectural and structural engineering perspective, with an emphasis on: creative solutions to project’s program requirements; applications of innovative design approaches in areas such as connections, gravity systems, lateral load resisting systems, fire protection and blast; aesthetic and visual impact of the project; innovative use of architecturally exposed structural steel (AESS); technical or architectural advances in the use of the steel; and the use of innovative design and construction methods.

“The innovative use of timber and steel in the atrium creates a warm and inviting space,” commented Matthew Kan, a graduate student at Northwestern University, and the student judge in the competition.

Recently completed by the U.S. General Services Administration (GSA) for the Seattle District of the U.S. Army Corps of Engineers (USACE), the Federal Center South Building 1202 transforms a 4.6?acre brownfield site into a highly flexible and sustainable 209,000-sq.-ft regional headquarters. The building has achieved LEED Gold status and ranks in the top 1% of the most energy?efficient buildings in the U.S.

The building, which meets USACE’s need for a more productive and collaborative workspace, used steel to creatively solve a number of specific program criteria and site challenges: a perimeter diagrid to defend against progressive collapse; architecturally exposed floor framing synchronized with mechanical, lighting and acoustical systems; integration with reclaimed timber floor framing in the building’s “Commons,” blast protection at the building envelope and “Energy Piles.”

Building 1202 responds to both the 2009 American Recovery and Reinvestment Act (ARRA), which focused on improving the country’s infrastructure and creating jobs, and the GSA’s Design Excellence program, which establishes nationwide procedures for selecting the finest architects and integrated design teams for GSA commissions. Building 1202 was planned, designed and constructed in less than 2.5 years, and stayed within its original $68 million design and construction budget.

The design organizes functions into two distinct forms, each with its own structural system and innovative approach. Open offices take shape around an oxbow-shaped exposed steel structure and perimeter diagrid. In the central core, conference and teaming rooms are constructed of reclaimed lumber and an innovative composite wood and concrete assembly supported on steel girders. These diverse structural systems not only meet the demanding structural requirements, but are also key contributors to the overall architectural expression and performance of the project. And the building’s form pays tribute to the site; it is located at one of the last remaining oxbows of the original Duwamish Waterway and is actually situated on fill deposited when the Corps dredged and straightened the waterway in the early 1900s.

A perimeter diagrid was employed to serve against the progressive collapse design requirement. The diagrid consists of sloping columns and spandrel beams with bolted (pinned) connections between the members and creates an efficient and inherently redundant structure. Compared to a conventional moment frame approach for solving progressive collapse, the diagrid system achieved savings (and used less labor) by eliminating pile foundations, reducing the steel tonnage by 30%, accelerating the erection schedule and eliminating full-penetration welds at connections between the spandrels and the columns. It also achieved smooth transitions through the curved portions of the building, facilitated by the diagrid, by utilizing a tangential variation at each floor line. This allows the exterior skin to easily transition through the corners of the U?shape, resulting in a smoother appearance. The diagrid is painted white throughout in order to assist in diffusing both natural and artificial light inside the building and also to be prominently visible through the exterior glazing. It is celebrated as an integral part of the building’s architectural expression as well as a physical manifestation of the Corps’ motto of “Building Strong.”

Since the steel floor framing is exposed, the layout of the steel members was synchronized with the workstation sizes and the ceiling solutions for the lighting, chilled beams (mechanical system) and acoustics. In addition, steel girders and connection materials were integrated with an innovative composite reclaimed timber?concrete beam framing system in the central Commons; steel and timber were also integrated on the stairs and pedestrian bridges.

Structural steel framing was used in combination with light-gauge steel to resist blast loads on the building’s perimeter envelope, and the steel trusses in the atrium were also designed to meet blast requirements. The building is supported by 205 steel pipe piles that extend through soft, liquefaction?prone fill and alluvial soil. The piles are 150 ft to 175 ft long and derive support in dense glacial soil; 135 of the piles contain ground source heat exchange loops, creating “Energy Piles” that form the backbone of a geothermal system that works in concert with the building’s high-performance mechanical systems. This is one of the first projects in the region to combine geothermal heating and cooling systems with structural piles.

The IDEAS2 award dates back more than 70 years to the earliest years of AISC’s existence. And about this year’s winning federal building, Roger E. Ferch, P.E., president of AISC, said, “The U.S. Army Corps of Engineers Federal Center South Building 1202 project team has shown how structural steel can be used to create structures that combine beauty and practicality. The result is a structure that serves its employees extremely well, while providing an example of what can be achieved when designing and constructing projects with steel.”

High-resolution images of the U.S. Army Corps of Engineers Federal Center South Building 1202 project are available upon request by contacting AISC’s Tasha Weiss at 312.670.5439, . For more information about the IDEAS2 awards and to view all of this year’s winners, visit

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