Honorable Mention, Addition
80 M Street is the first-ever mass timber renovation of a commercial office building in Washington, D.C. Located in the Navy Yard, the project adds 107,000 square feet, or three floors, constructed primarily of mass timber and glass curtainwall to the existing 7-story, 265,000-square-foot building.
At 128-feet-tall, 80 M Street fell below D.C.’s height limit, and owners of the high-performing building sought to maximize its vertical density. The decision to use mass timber was driven by multiple factors, chief of which was its light weight. Recognizing its value as a differentiator within the highly competitive D.C. office market, the owner and project team entered an exploration period.
Given mass timber’s novelty, the extension design underwent a thorough vetting process before it was approved by D.C. code authority. A critical focus was the structure’s connections because of a lack of fire-tested connections on the market. The structural and fire engineers developed new concepts for custom-concealed, two-hour- rated mass timber connections, a consideration not addressed prescriptively within code. The timber design-assist contractor further detailed and tested the custom connections to secure final approval. Close collaboration with local code officials helped establish an alternate compliance path to allow mass timber to be used within the current permitting process. As a result, CLT was accepted as floor panel under IBC 2021. A hybrid solution combined construction types IV-C and IV-B to address the project’s unique position of only being 3 stories of timber but exceeding the allowable 85-foot height limit for construction type IV-C.
The result is a one-of-a-kind office experience. Terra-cotta wall panels and painted metal exterior elements complement the existing brick façade of the original floors while adding a pop of color that ties in with the neighborhood’s bold design aesthetic. A new canopy structure hangs above the top floors to shield the interior from southern sun exposure. The building’s faceted aluminum soffit battens, visible from street level, are designed to look like wood while adhering to fire-safety protocols.
Two new levels of Trophy Office space feature exposed natural wood and 16-foot-tall slab-to-slab heights, improving depth of light penetration by almost 200 percent. On the new eighth floor, a portion of the exterior glass line steps back to create a private tenant terrace. A third penthouse level offers a combination of private office and shared amenity spaces.
80 M Street incorporates approximately 1,400 tons of mass timber, which took just eight weeks to install.
PHOTOS: Ron Blunt unless otherwise noted
Retrofit Team
METAMORPHOSIS AWARD WINNER, ARCHITECT AND INTERIOR DESIGNER: Hickok Cole
GENERALCONTRACTOR: Davis
ENGINEER: Arup
Materials
MASS TIMBER: Mercer International
CURTAINWALL: Frame from Erie Architectural Products and Glass from Viracon
TERRA COTTA: Terreal
ELEVATOR: Otis
GREEN ROOF: Henry
PAVERS: Archatrak
OPERABLE PARTITION: Modernfold
MOVABLE GLASS WALL: NanaWall
LIGHTING CONTROLS: Lutron