The LEED Platinum-certified GSA Federal Center South Building 1202 transforms a brownfield industrial warehouse site into a highly flexible and sustainable 209,247SF workplace for the U.S. Army Corps of Engineers (USACE) Seattle District headquarters. The concept for the building—the Oxbow—provides the greatest flexibility for work groups to expand and contract as needed, while its narrow floor plate optimizes daylight penetration. The Oxbow alludes to the bend of the adjacent Duwamish Waterway, and our cultural memory of artist Thomas Cole's 19th c. notion of sublime in "The Oxbow" vis-a-vis westward exp expansion, realized here in Seattle. Open plan workstations surround the central “commons” that houses all shared resources, including conference rooms, kitchenettes, the library, and informal seating areas to encourage interaction and create a sense of community. The design integrates active and passive systems, materials, and strategies to achieve aggressive water and energy saving requirements. The project is one of the first in the region to use structural piles for geothermal heating and cooling, as well as phase-change material and thermal storage. Chilled sails and open office lighting were developed and manufactured specifically to help achieve aggressive energy targets. Daylight, solar control, an intelligent envelope, and a rainwater reuse system are also all integral to the high-performance design. The reclamation of 200,000 board feet of timber from a warehouse previously located on the site provides a dramatic interior environment. The landscape extends into the building performance design. The reclamation of 20 200,000 board feet of timber from a wa warehouse previously located on the site pr provides a dramatic interior environment. The landscape extends into the building performance design. The reclamation of 200,000 200,000 board feet of timber from a warehous warehouse previously located on the site provides provides a dramatic interior environment. The landscape extends into the building performance design. The reclamation of 20 200,000 board feet of timber from a wa warehouse previously located on the site pr provides a dramatic interior environment. The landscape extends into the building performance design. The reclamation of 200,000 board feet o 200,000 board feet of timber from a warehouse previously warehouse previously located on the site provides a dramatic provides a dramatic interior environment. The landscape extends into the building performance design. The reclamation of 20 200,000 board feet of timber from a wa warehouse previously located on the site pr provides a dramatic interior environment. The landscape extends into the building performance design. The reclamation of 200,000 2 200,000 200,000 board feet of timber from a warehous warehouse previously located on the site provides provides provides a dramatic interior environment. The landscape extends into the building performance design. The reclamation of 20 200,000 board feet of timber from a wa warehouse previously located on the site pr provides a dramatic interior environment. The landscape extends into the building’s light-filled atrium, creating a pedestrian spine from the entry plaza through the building to the west terrace. The transparency afforded by the building’s glazing creates a strong visual connection between the interior and exterior, reinforcing the facility’s physical and conceptual relationship with the Duwamish. Federal Center South's optimized form, systems, and orientation enable it to p perform within the top 1% of U.S. energy-efficient office buildings.