Consider the numerous publications romantically chronicling lost architectural gems, including Lost New York by Nathan Silver (1968), Capital Losses: A Cultural History of Washington's Destroyed Buildings by James Goode (1979), Lost Boston by Jane Holtz Kay (1980), and Lost Chicago by David Garrard Lowe (1975). These richly illustrated publications have become both a call to action and a mandate for responsible stewardship of our great urban architectural legacy. There are also "then and now" pictorial guides that use photographic pairings to chronicle the changed urban landscapes of Washington DC, Chicago, Boston, Baltimore, Philadelphia, and scores of other cities. "Then and now" pairings are certainly intriguing and prompt nostalgic longings for the past, but they offer little critical analysis about why urban fabric changes.

Cities are constantly undergoing change, either aided or hindered by myriad emotionally and politically charged planning processes. Can what is lost and what is destined to change capture the public's interest? How can historians and preservationists engage the public in a more effective way? When managing change, who gets to decide what is retained or changed? And how is success measured?

In many cases, public engagement is critical. In the new urban regeneration scheme of New York's High Line—a masterful combination of design and historic preservation—public engagement helped the design competition generate 720 entries from thirty-six countries. The World Trade Center Site memorial competition yielded 13,683 registrants and 5,201 memorial submissions from sixty-three nations. Broad public engagement such as this is apt to bring forward unexpected and entrepreneurial designs that intelligently address the challenges faced.

With public engagement in mind, let us consider recent threats to three modern works of architecture and landscape architecture. In each case, a rehabilitation solution has been put forward, advanced by a coalition of advocates from the design and historic preservation communities.

First is Chicago's Prentice Women's Hospital (Bertrand Goldberg, architect, 1975), owned by Northwestern University. In an entrepreneurial bid to stop demolition, the Chicago Architecture Foundation (CAF) promoted a public discussion about the fate of the hospital and other modern icons, titled "Re-use It or Lose It," as part of its Chicago Debates series. In addition, CAF, in collaboration with two other organizations, held a Future Prentice design competition, which challenged designers to restore, modify, or expand Prentice Women's Hospital. Separately, New York Times architecture critic Michael Kimmelman, advocating for a design by Chicago-based architect Jeanne Gang, declared that "Northwestern needs to avoid the ignominy of having torn down a landmark. And sometimes a third way is the best way."

Second, consider Peavey Plaza in Minneapolis, a modern, two-acre public space adjacent to Orchestra Hall. Completed in 1975, Peavey Plaza is the most important extant work designed by M. Paul Friedberg. It is the nation's first "park plaza," a landscape typology that Friedberg created, and which he describes as "a mixture of the American green space and the European hard space." In January of this year it was listed in the National Register of Historic Places. Municipal officials and representatives from Orchestra Hall, currently undergoing a major renovation, have decided that the poorly maintained Peavey no longer works for them. They argue that complete restoration is onerously expensive and that there are no reasonable alternatives to demolition and replacement.

To stimulate public discourse and involvement, Friedberg, at his own expense, came up with a richly illustrated alternative concept that addressed the city's site-specific design and safety challenges. The preservation community, Peavey Plaza supporters, and the original landscape architect are not proposing restoration; rather they advocate an adaptive reuse and conserving significant historic features, an approach that would maintain the site's character and defining features while addressing accessibility and programmatic issues. Nearly 70 percent of the participants in a Minneapolis City Pages online poll reject demolition, and a recent article in the business-oriented Minneapolis Finance and Commerce newspaper cited architects who said that the National Register designation should prompt city officials to reconsider their position. Nevertheless, the city is holding firm on demolition.

Finally, there is the Charlottesville Mall in Charlottesville, Virginia, an eight-block-long, sixty-foot-wide street designed in the mid-1970s by Lawrence Halprin and Associates, the only surviving Halprin-designed project in Virginia. (The other, a sculpture garden at the Museum of Fine Arts in Richmond, was demolished as part of the museum's expansion.) The mall, which serves as Charlottesville's open-air living room, is notable for the inclusive, citizen-based design process that informed its creation, its many subtle and innovative design solutions, and its careful regard for the area's social, economic, and architectural history. Its signature design element is four-by-twelve- inch utility brick, widely used in streets and alleys across America before the popularization of macadam and asphalt.

Following years of deferred maintenance, the city proposed numerous changes to the mall, including the addition of new fountains, play areas, and public art, and replacement of the signature bricks with standard four-by-eight-inch bricks. Collectively, these changes would have radically altered the mall's look and compromised Halprin's design. A coordinated public outreach campaign—accompanied by documentation of the site by University of Virginia landscape architecture students—ultimately shifted the discussion to rehabilitation of the Halprin design. Many of the proposed design elements were abandoned, and the signature four-by-twelve-inch bricks were retained.

I have long argued that the preservation movement, particularly when dealing with modern landscape heritage, must build bridges with designers, ecologists, and others and offer articulate, well-illustrated, and evocative solutions. In these three instances, efforts to broaden the conversation beyond traditional preservationists succeeded to varying degrees. These cases also demonstrate that when there is a diverse coalition—and the political will—the focus of efforts should be on innovative and embraceable rehabilitation preservation solutions.

Charles A. Birnbaum is the founder and president of the Cultural Landscape Foundation.