The Accolade

The Accolade is the adaptive reuse of 1425 New York Avenue, NW, a former 13-story office building with a penthouse level and four below-grade garage levels that was converted into 243 apartments and completed in 2025. The third floor and above were added in the early 1990s as part of a vertical expansion. Typical floors consist of one-way, 5-inch-thick post-tensioned (PT) slabs spanning between PT concrete beams.

Material testing, field verification, and ground-penetrating radar (GPR) tendon mapping informed the design. To meet residential daylighting requirements, the atrium was enlarged through partial demolition of the PT structure, with tendons re-anchored and restressed at each new slab edge. The atrium’s north edge was extended with a new slab cantilevered from a PT beam. Where roof girders were partially demolished at the elevator machine room, new columns extending from Level 3 to the upper levels support the remaining girders.

The penthouse (PH) was rebuilt in steel on a new footprint, incorporating screen walls, dunnage, and canopies. Steel beams at the Level 13 soffit transfer loads from PH posts to existing columns or girders. The roof includes a green roof and occupiable amenity space. Other work included a Level 2 canopy, prefabricated balconies, façade support modifications, slab infills, new shafts, and slab cores.