20 Massachusetts Avenue, NW
Washington, D.C
BEST PROJECT
Sent by: DPR construction
Owner: The RMR group
Main design company: Leo A Daly
General contractor: DPR construction
Civil Engineer: Bohler DC
Structural Engineer: SK&A
MEP Engineer: Interface engineering
Landscape architect: Lee and Associates Inc.
Owner’s representative: Mark G. Anderson Consultants Inc.
In just over two years, the seven-story office building from the 1970s was reimagined as a 485,000 square meter mixed-use destination. It combines a 274-key luxury hotel with A-class office space, all complemented by many amenities. To achieve this unusual repositioning, the original exterior skin and interior were stripped down to the structural frame and concrete floor slabs. The project team then added three stories to the structure and expanded the footprint by one column bay, creating 101,000 square feet of new space.
Photo courtesy DPR Construction
Because the building’s trapezoidal shape limited natural light inside, the project team installed steel braces and cut out large sections of floor slabs to accommodate two atriums. A full-height 10-story atrium is topped with a 2,400-square-foot skylight; the second rises four stories. Auricle slab clippings and roof demolition generated 10,000 tonnes of concrete and other waste, of which 75% was recycled. Combined with a unified glass curtain wall facade, the once opaque concrete structure is flooded with natural light for a seamless connection between indoors and outdoors, the team says. The approach also reduced the depth on all sides of the building, allowing for an additional 60 rooms.
Photo courtesy DPR Construction
Achieving this $151.6 million transformation required addressing many unforeseen conditions, including undocumented asbestos, inconsistent floor slab flatness between columns, and a column grid line discrepancy that required adjustments to the stacked arrangement of the rooms. Virtual design and construction technology proved instrumental in addressing these and other issues and fostered collaborative problem solving to maintain the project schedule. A narrow alley with an active loading dock and garage adjacent to the building’s west facade required the use of precision-engineered precast facade panels to preserve access and ensure worker safety during construction.
Photo courtesy DPR Construction
Other features of 20 Massachusetts Avenue include a green roof with drought-resistant plantings, an integrated stormwater management system that reduces water consumption by 40%, and high-performance glazing that is expected to reduce the energy consumption by 20%. The project also marked the District of Columbia’s first installation of factory-custom bathroom pods, streamlining construction and minimizing waste. The 206 pods, which include Italian tiles, custom vanities and glass showers, were manufactured concurrently with the hotel’s construction phase.
