To start with a remarkable statistic, of the 400 most populous places in the United States, only the New York metropolitan area has more people per square mile than Somerville. For a population of 81,500, compressed into just 4.1 square miles, Somerville is denser than almost anywhere else in the country, including Cambridge and Boston. So, as the city continues to get even denser, it has to do so differently—think mobility, access to open green space, community character, and climate change and sustainability objectives. Development of even a 2-acre parcel can have a major impact on the urban life of a local community.

The former 1960s Powder House school is located in Teele Square near the Tufts University campus and is a few minutes’ walk to the vibrant commercial activity of Davis Square. Well served by bus and train service, many area residents shun driving for walking, cycling, or public transit—soon to be further enhanced when the nearby Somerville Community Path provides a direct bicycle route all the way to Boston.

In 2004, the city closed Powder House’s doors due to underutilization and excessive building maintenance costs. The building’s windowless perimeter walls—similar in design to many urban public schools of its generation—were like a protective barrier for its young inhabitants against the outside world. The interiors received natural light solely from a small interior courtyard.

Since the school’s closing, neighbors have been keen to influence the outcome of the site’s redevelopment. After many years of community input, a shared vision finally emerged on key terms: the need for accessible open/public green space, modest development, and affordable housing. Few thought the mothballed school building could be feasibly preserved.

In 2015, after unsuccessful attempts to dispose of the property, the City of Somerville readvertised for proposals to develop the former school with an emphasis on aspirational criteria derived from the community. There were three ways this development could have gone: 1) demolish the bunker-like school building and construct a new enclave; 2) repurpose the school with a new program, adding windows into the blank exterior walls; or 3) do something bold.

The community chose the latter option.

Eight developers responded to the request with housing or mixed-use proposals. Sebastian Mariscal Studio and MarKa, the development arm of the studio, submitted the winning proposal: a striking vision to turn the school building inside out, weaving together the public park and repurposed building, and inviting creative and community-focused activities in to fashion a new, live-work, mixed-use development. (Full disclosure: I crossed paths with Powder House twice, first on behalf of an independent elementary school looking for a new campus and later when serving on the Somerville Design Review Committee.)

Adaptive reuse

From the outset, perhaps the most consequential decision the architect made was to reuse the original building’s concrete frame. The fortresslike block enclosure walls and interior systems were demolished, dramatically transforming the building into an open framework for the introduction of fundamentally different functions and enclosure methods.

The project continued to be refined throughout construction. As demolition progressed, unexpected conditions were revealed and details of the design reconsidered. Perhaps the biggest surprise was the increased scope of structural upgrades required to meet the building code, such as the addition of more shear walls and the extent of column reinforcing. Seeing an opportunity, the architect embraced these challenges as a way to enhance the architectural character of the redevelopment.

As a result, there was no attempt to patch minor damage to the structure or clean up traces of paint from a classroom interior. Rather than encapsulate the shored-up concrete frame, the building structure is presented as a found object, a remnant of the original place. Its past life will have resonance as it literally and figuratively supports its own creative reuse. As a case in point, two-story structural piers revealed during demolition required unsightly steel bracing and were left exposed to view. “I call them the Frida Kahlo columns,” Mariscal quipped, alluding to the bracing. The existing structure’s rough, unvarnished presentation will be juxtaposed against the contemporary detailing of the new building enclosure, most evident in the tall commercial storefront along Broadway, and window and mural walls running throughout the building.

Public space

The former school’s largely paved play yard is now being transformed into a public park, connecting through the site from Holland Street to Broadway and meandering into the courtyard of the renewed complex. In response to extensive community input, the Mariscal design creates a neighborhood asset and destination. Residential units open directly to the public courtyard as urban homes open to the street, blurring the line between public and private open space. More than 50 percent of the site is publicly accessible, exceeding the required 40 percent from the city’s request for proposal. Designed with Somerville landscape architect GroundView, the park encourages intergenerational use; spontaneity; and flexible programming for community uses, including gardens, performance areas, and, by popular interest, bicycle repair.

Sustainability

Fundamental to the design vision was seeing how the conditions of Powder House could leverage a broad agenda of environmental goals. The reuse of the former school building structure is an obvious example of resource conservation. The roof will host a solar farm of photovoltaic arrays for producing onsite renewable energy. Demounted concrete spandrel panels were salvaged and repurposed as park benches. The compact layout and elimination of corridors translate to less building to build (resources) and less space to heat and cool (energy), while also furthering residents’ connection to public green space. A rain garden and other site systems will also contribute to the sustainability program.

Program

Mirroring the creative character of broader Somerville, the community-focused program of the 91,000-square-foot building has been a fluid component of the development process. The housing program has remained at 48 rental units (20 percent affordable), with a mix of townhouses, 12 senior-living units for those aged 55 and older, and eight artist live-work units. But commercial, makerspace, and community tenants have been harder to pin down. Disappointingly, a 160-student alternative innovation high school has had to pull out of the development. On a positive note, the Collaborative Living Project—a group of senior artists, activists, and educators—will occupy eight of the senior-living units.

Art

Artists will live, work, and exhibit on site. Public space is designed to invite performance, live arts, and art installations. Ultimately most visible will be the building’s unique mural program. Inspired by the Mexican tradition of expansively painting buildings—even whole towns—with vivid art, the complex will host 74 mural locations covering 4,320 square feet of wall surface. Walls surrounding the building and lining the courtyard, exclusive of windows, will don murals. Artist selection is just starting and aims to draw from national as well as local talent. Murals will be commissioned and painted over a period of a few years, continually transforming the building. Asked if he intends to curate the murals, Mariscal said he will not limit the artists’ creativity or content: “I want to lose control of this program.”

The extent of Powder House’s bold idea can be seen in person as the building begins to take shape and the contours of its vision become apparent. Construction fences come down this spring, and new residents and commercial tenants will move in. Mariscal hopes the public will begin to traverse the park and feel enticed to explore the reaches of this art-driven place.

This vision feels particularly instructive as Somerville becomes ever denser. Perhaps Powder House, as a compact urban village set amid flexible-use open space, can serve as a lesson for the city going forward—a development model for the future.