Atlantic Council Repositioning

Atlantic Council’s new headquarters was relocated to The Aleck, a 12-story office building at 1400 L Street originally constructed in 1987. The ambitious vision for the new office space spans five floors, highlighted by a signature multipurpose room (MPR) on the 11th floor. Designed as a two-story volume with an open floor plan, the MPR posed significant structural challenges. The original 1980s building utilized 20’-0” x 20’-0” bays with a modest 10-foot floor-to-floor height. To realize the column-free space, the 12th-floor slab was selectively demolished within the MPR footprint. Three interior columns were removed, following the installation of new post-installed, post-tensioned long-span beams beneath the MPR roof to successfully carry the redistributed loads.

Complementing this centerpiece, a new assembly space was created through a terrace expansion cantilevered from the existing 11th floor. This was achieved by extending the perimeter concrete beams and integrating new structural steel framing with lightweight concrete topping over a metal deck system. The result is a dynamic, flexible environment that seamlessly merges engineering ingenuity with architectural vision.