Federal Center South, Building 2021

This Design-Build project is a redevelopment/modernization of an existing early 1940s warehouse located at the Federal Center South campus in Seattle, Washington. The facility provides approximately 200,000 gross square feet of office space for the tenant, the United States Army Corps of Engineers (USACE). The three-story structure is shaped like an oxbow. It houses a large commons area at the center and a wraparound skylight system above the atrium that emits an abundance of natural lighting.

In order for the General Service Administration (GSA) to lease the building to the USACE the building needs to meet the Unified Facilities Criteria (UFC) 4-010-01, DoD Minimum Antiterrorism Standards for Buildings dated October 8, 2003 including change 1, 22 January 2007. Hinman worked with KPFF Consulting Engineers and ZGF Architects to implement Standard 8 and 10 from the UFC. The primary objective was to provide a safe, as well economical and energy efficient design, for the supporting structure of all glazed systems.

To achieve a Gold LEED certificate, Hinman and KPFF collaborated to develop an insulated light gage box beam spanning between kicker systems to transfer the air-blast load to the supporting structure.

Typical façade design for UFC buildings meeting conventional construction, 148-ft standoff, consists of implementing the static procedure presented in UFC 4-010-01, however due to the size of the window panes an economical design could not be achieved by implementing the conventional method. Alternatively,

Hinman performed dynamic analysis of the glazed systems in order to achieve the project’s goals. A ribbon window supported by a kicker system framing back to the top face of the composite deck was developed to transfer the air-blast loads back to the building’s floor slab. Additionally, this was an aesthetically pleasing solution due to the raised tongue-and-groove wooden floor covering the HSS tube kicking back to the structure. Moreover, in support to achieve a Gold LEED certificate, Hinman and KPFF collaborated to develop an insulated light gage box beam spanning between kicker systems to transfer the air-blast load to the supporting structure. In order to achieve a safe, however lean design, Hinman determined the peak pressure and impulse at the atrium from detonation of the Design Basis Threat (DBT) stipulated in the UFC.

Hinman also provided a design in compliance with Standard 8 from UFC, an Antiterrorism standard which mitigates damage at overhangs with inhabited space above and considered the effects due to a lobby threat per GSA’s request. A reinforced CMU partition wall separating the unsecure portion of the main lobby from adjacent offices and a hardened composite slab above was incorporated in the design documents in order to protect employees working in the offices above and adjacent to the lobby.