A prominent anchor in Capitol Hill’s core, the project at 20 Massachusetts Avenue, NW consisted of an addition and re-skinning of the existing eight-level 437,000-sf office building. The program included a penthouse amenity level and two levels of below grade parking. Two additional floors were added to reclassify the building as a Class A mixed-used typology, bringing the total square footage to 546,250.

Interface Engineering provided a design study to analyze the existing building systems in relation to adding the two floors, a new interior atrium, and reorganizing the building to include retail at the ground level, the mid-level luxury 274-key Royal Sonesta hotel, office space on the upper levels, and roof deck amenities. Based on resulting recommendations, Interface provided the mechanical and electrical engineering design, as well as lighting, energy modeling and commissioning. Sustainable features were implemented throughout the building including enhanced ventilation for improved indoor air quality, daylighting, low flow compliant fixtures, and a green roof with drought-resistant planting.