20 F Street, NW
Washington, D.C.

Construction is complete and tenant build-out is underway for the future headquarters of the American College of Surgeons. We provided structural design to Evans Heintges Architects PLLC for the 10-story, 235,000-sf Class A office building with 60,000 sf of below-grade parking. The structural system consists of flat-plate post-tensioned concrete. The project involved extensive underpinning of adjacent buildings, including a 100-year-old local landmark, the Irish Times Pub. Challenges included the discovery of unexpected existing conditions during excavation. Underpinning pits for a previous building on the site attached to an adjacent building had to be cut with a rope saw, a dangerous and time-consuming process. Existing foundations also encroached over the property line on both sides of the site, requiring a last-minute redesign of several areas of the building to accommodate the reduced footprint. Boston Properties was the development manager for the American College of Surgeons.