From the standpoint of the Old World, where people have been converting buildings to new uses since before the ancient Romans decided to adapt much of Europe for their own purposes, America is a latecomer to the idea of adaptive reuse. Even as recently as the 1960s, "most architects and most people thought, 'Well, everything has to be new, and we're just going to demolish things and build all new construction,' " says Andrew Wolfram, an associate principal at Perkins+Will and a commissioner on the San Francisco Historic Preservation Commission. So in 1962, when William Wurster looked at the 19th-century brick structures of the former Ghirardelli chocolate factory and saw not a teardown but the makings of a waterfront retail and restaurant attraction, he changed the city's—and the nation's—relationship to its architectural heritage. Once San Franciscans got a look at their first converted warehouse, "it was absolutely trend-setting in terms of San Francisco and its attitude about what could happen to existing buildings," says Jay Turnbull, principal at Page & Turnbull and former president of San Francisco Architectural Heritage, the city's historical-preservation society.
Nearly 50 years later, warehouse condo lofts are practically a real-estate cliché. But the city, the host of this year's Greenbuild International Conference and Expo, boasts a more recent crop of adaptive-reuse projects, from the Presidio Trust's ongoing transformation of a former army post into a residential national park to HOK's ambitious conversion of the old San Francisco Mint into a zero-energy-capable museum of the Bay Area. "This year's Greenbuild theme focuses on uniting sustainability and technology in the global green-building movement, and there's really no better place than San Francisco to bring that idea to life," says Kimberly Lewis, senior vice president of community advancement, conferences, and events at the U.S. Green Building Council.
San Francisco has made much of its good industrial bones since Ghirardelli. Yet many opportunities to repurpose city landmarks were born of disaster. The 1989 Loma Prieta earthquake crumbled highways and rendered many structures unsafe. With the demolition of the Embarcadero Freeway, which had cut off the city from its northern shore, San Francisco began reconnecting itself to the waterfront. "Suddenly the piers were these amazing structures that were underutilized," says Perkins+Will design principal Cathy Simon, whose former firm, SMWM, repurposed the warehouse at Pier 1 as offices and a public promenade in 2001, followed by the Ferry Building in 2003. Both buildings used a first-of-its-kind (in San Francisco) bay-water heat-exchange system to warm the floors with radiant heat.
Ford Assembly Building
On the Richmond waterfront, at the northeastern side of the bay, the earthquake also battered an icon of the region's industrial past, the Ford Assembly Building. Designed in 1931 by Albert Kahn, the factory was the largest assembly plant on the West Coast, at one-fifth of a mile long. Marcy Wong Donn Logan Architects' large-scale renovation transformed the deteriorating structure into an expansive monument to the Bay Area's new economy. The 525,000-square-foot Ford Assembly Building, which opened in 2009, now houses companies such as the solar-panel maker SunPower under its giant sawtooth-skylight roof. At the waterfront end of the complex, the architects repurposed the factory's acre-size pier into the Craneway Pavilion, a performance and event space with approximately 60-foot-high ceilings and original cranes left over from the plant's shipping days. A rootsy restaurant in the former boiler room and a visitor center for the National Park Service round out the program.
Because of the Ford plant's historic appeal—it's on the National Register of Historic Places—the architects wanted to choose sustainable features that would be practical as well as compatible with preservation. Rather than cover up the existing concrete floors with radiant-heat slabs, the team used forced air for much of the project. But on-site renewables make up for this compromise: The assembly building generates a great portion of its energy from solar panels that SunPower installed on the structure's south-facing roof. And thanks to the Bay Area's mild climate, the entire complex relies on natural ventilation: It has 40,000 windows, most of them operable. "It was better to have the production of green energy than to spend the resources to get rid of serviceable windows and replace them with new ones," says Marcy Wong.
Before the city's industrial heyday, the U.S. Army was the main presence along the San Francisco waterfront. Active between 1846 and 1994, the Presidio (now part of the Golden Gate National Recreation Area) functions as a kind of time capsule chronicling the evolution of San Francisco over nearly 150 years. The Presidio is home to a 300-acre forest and upwards of 700 buildings—more than half of them historic—making its redevelopment equal to the adaptive reuse of an entire city. Since 1994, the Presidio Trust has been managing the transformation of the site into a kind of live-in historic park, converting masonry officers' quarters, social clubs, and hospitals into tastefully restored apartments, restaurants, stores, and cultural attractions. The Thoreau Center for Sustainability, an early adaptive-reuse project begun in 1995, turned a crumbling 1899 hospital complex into office space for more than 60 nonprofits, and was the first project at the Presidio to incorporate solar photovoltaics.
One of the best examples of sustainable adaptive reuse in the park is the Presidio Landmark District, where the residential conversion of the former Public Health Service District is pending LEED for Neighborhood Development certification. KieranTimberlake and San Francisco–based WRNS Studio designed the new Belles Townhomes, which incorporate rooftop solar panels, and a team including Page & Turnbull renovated former doctors' quarters for additional housing. But the centerpiece of the neighborhood is the six-story 1932 Colonial Revival brick-and-stone hospital, completed by Perkins+Will in 2010. To adapt the hospital for the new Landmark Apartments, the architects found a clever solution for carving out sizable, light-filled apartments from the hospital's too-narrow wings: They oriented the units horizontally, along the windows, using a jigsawlike configuration of 32 different unit types. "We were trying to take the character-defining features of the building—its long wings—and run with it, not fighting the building, but understanding that and making that the feature you celebrate," says Wolfram of Perkins+Will, which received LEED-NC 2.2 Gold for the project. In addition to taking advantage of the Landmark's operable windows for natural ventilation and cooling, the architects were able to combine hot water and radiant heat into one system for greater efficiency.
On the Presidio's main post, Architectural Resources Group (ARG) completed the park's first hospitality project, the Inn at the Presidio, in April. Formerly known as Pershing Hall, the 1903 Georgian Revival consisted of two-room units for bachelor officers. ARG repurposed these as two-room suites, which allowed it to retain much of the interior. Energy savings reaped from the masonry structure's already good thermal character, a more efficient heating system, and a creative use of blue jeans for extra insulation helped earn the inn LEED Gold rating, as did a new rain garden. The 1,350-square-foot stormwater-treatment bay reduces peak runoff by more than 50 percent and helps restore the park's watershed.