In 2015 Oehme, van Sweden (OvS) was selected to redesign the rooftop for the Modernist library originally designed in 1972 by architect Ludwig Mies van der Rohe.
Spanning more than 26,000 square feet, two vast green roofs, one of which sits on a raised deck atop the main roof of the library, feature draught-tolerant perennials as part of an extensive stormwater filtration system. The plantings also serve to mitigate the urban heat island effect, while both softening sightlines to the surrounding taller office buildings and simultaneously affording garden views for their inhabitants. Directly below is the publicly accessible 17,250-square-foot fifth floor terrace, with its array of irregularly-shaped raised planting beds and integral wood slat benches, strategically placed throughout the paved roof deck. The planters are grouped into miniature gardens, such as the Native Pollinator Garden, Garden of the Senses, and Seasonal Viewing Garden.
To engage with the sidewalk at ground level, street trees in oversized planters, sited among large granite pavers that recall the materiality of the roof deck above, merge the library’s landscape with the broader urban context and draw library goers into the site. During the course of the project, architects Mecanoo and OTJ Architects removed a parking garage at the rear of the building, enabling OvS to extend an existing terrace to include ample cafe seating with movable chairs surrounded by shade trees. This flagship branch of the District of Columbia Public Library (DCPL) reopened to the public in September 2020. The structure was listed in the National Register of Historic Places in 2007.