Project Description1525 14th Street, NW
The 14th Street Corridor between N Street and Florida Avenue, NW, has been booming over the past decade. Most of the recent development has consisted of retail, restaurant, and residential projects, which animate the neighborhood in the evenings, but less so by day. In that context, the owner of the property at 1525 14th Street sensed an opportunity and perhaps even a civic responsibility: by developing a speculative office building on the tight site, he could bring daytime activity to 14th Street while creating a more mixed-use atmosphere, to the benefit of local residents and businesses alike.
The mid-block site included an existing, historic building that was once part of Washington’s “Automobile Row” of early 20th-century car dealerships, plus a surface parking lot that was a “missing tooth” in the increasingly vibrant streetscape. The three-story existing building, with its dignified, neoclassical stone façade, was already occupied by a popular restaurant and several smaller tenants, and would have to remain in full use during the construction of the addition, consisting of two new floors above plus six stories of space on the parking lot next door.
The design by Eric Colbert & Associates is technically an addition, but it neither overwhelms nor competes with the historic building. Instead, the new construction complements the original structure through sensitive aesthetic contrast. Responding to the simple elegance of the historic building’s neoclassical façade, the street front of the addition is unpretentious, sophisticated, and modern.
In an era in which many new commercial buildings are sheathed in flat glass curtain walls, 1525 14th is distinguished by the visual depth of its main façade. A tartan grid of gray zinc panels projects slightly beyond the main plane of the new façade, creating a sense of layering while also lending vertical emphasis to the composition. The height of the first two floors mirrors that of the lower two floors on the original building. The tall, zinc-clad columns allude to the neoclassical pilasters on the earlier building. Meanwhile, the proportions of the zinc-clad section, which extends to only five of the six stories in the addition, help to mediate between the scale of the new construction and that of the older buildings on the block.
Set back from the grid of zinc panels is a glassier portion of the façade with white spandrel panels. A vertical swath of that more transparent skin extends from street to roof at the center of the composition, simultaneously marking the main entrance to the complex and creating a visual buffer between the stone and zinc façades. The white-metal-and-glass cladding also appears on the addition over the original building, where its light color and high degree of transparency reduce its visual weight. The white portions of the façade include recessed frosted glass panels that add variety to the composition. These glass panes were designed to be illuminated at night to add even more interest to the building.
The main façade, which faces west and therefore can be exposed to intense afternoon sun, is punctuated by horizontal louvers. On the white-metal-and-glass sections of the façade, the louvers are also white, and extend uninterrupted across the surface, thus providing a horizontal emphasis that relates to the understated cornices of the historic building. Within the zinc-clad section of the façade, small glass louvers span the narrow windows, providing some solar protection but also serving to highlight the depth of the grid.
The project is in a historic district and required the approval of the D.C. Historic Preservation Review Board (HPRB) and the Board of Zoning Adjustment. In accordance with HPRB guidelines involving “contributing” structures to a historic district, the new floors above the existing building are set back substantially from the front façade. To make up for the loss of developable space that this entailed, we cantilevered the addition out over the rear of the existing building toward the alley. Rather than covering that rear façade in inexpensive brick or artificial stucco, as might be expected, the façade is clad in an elegant metal panel system similar to those on the main façade, a gesture that is surely appreciated by residents of the row houses across the alley.
The project entailed several significant technical challenges. The new section built on the former parking lot uses a cast-in-place concrete structure, but that would have been too heavy for the addition over the existing building, so we used steel and lightweight precast concrete planks there instead. The project also includes two levels of underground parking, accessible via a car elevator, since the site was too small to accommodate a ramp.
The completed building has achieved LEED Gold certification, reflecting close attention to environmental concerns throughout the design and construction processes. The project incorporates extensive green roofs, solar panels, and low-energy LED lighting, and provides ample bicycle storage to encourage non-car commuting. There is also a roof deck accessible to building tenants.
The restaurant and other original tenants remained in place throughout construction with minimal disruption to their activities. The entire addition has been leased by Whitman-Walker Health, a venerable local medical and social services organization.