Surrounded on three sides by bay and ocean, its roller-coaster topography dotted with parks, San Francisco lies on the Pacific Flyway, a major migratory pathway used by millions of birds during spring and fall. But the city’s dense urban core can act as a death trap. For example, buildings with glass façades are hazardous for birds: not recognizing transparent glass as a barrier, birds often try to fly through it, or, seeing vegetation reflected in glass, fly into it. During nighttime flights, they can become disoriented by brightly lit skyscrapers that obscure navigational stars and circle the buildings, confused, until they drop dead of exhaustion.

Over the past decade, several cities—Chicago, Toronto, and New York, to name a few—have proposed that developers, building owners, and managers adopt voluntary guidelines to reduce bird kills. But San Francisco’s new bird-safe building standards are the first with real regulatory teeth. In September, the city passed Standards for Bird-Safe Buildings, an ordinance that applies the bird-safe standards to all new buildings (and additions to existing buildings) proposed for buildings within 300 feet of open water or an urban bird refuge areas such as Golden Gate Park.

“We’re concerned about buildings that are close to habitat zones and resting spots for migrant birds,” says AnMarie Rodgers, the city’s manager of legislative affairs. 

The new standards provide specific guidelines for façade treatment, lighting design, and small wind generation features installed on buildings. The most significant change concerns the “bird collision zone” of buildings—the lower 60 feet where glass most often reflects vegetation—which must feature no more than 10 percent glazed windows, going forward. Solutions to the glass hazard include fritting the windows or screening them, which is the least expensive option. Lighting must be minimal and shielded; uplighting and event searchlights are prohibited. And buildings cannot feature horizontal-access windmills or vertical-access wind generators that do not appear solid.

City planners say that the standards related to window treatment have caused the most pushback so far, particularly the regulations that encourage fritting. Some city officials are among the critics. “They claim it’s not going to add a large amount to construction cost—if that were the case, it’s fine,” says planning commissioner Michael Antonini. “But some of these things start out and escalate to the point where they get larger and larger and more cumbersome, which discourages construction.”

But architect Deborah Laurel of Prendergast Laurel Architects examined the cost of treating 100 percent of an urban library’s windows and found that fritting would increase cost by less than half of a percent. And Rodgers points out that the bottom 60 feet of a building’s façade “is not a substantial portion of the building. We expect that as the market increases, costs will go down.”

Rodgers also thinks that the standards will save developers money in the long run. After facing years of challenges from environmental groups to proposed waterfront developments, she realized that last-minute changes to projects to mitigate the impact on birds were extremely costly. “That crystalized it for me,” she says. “Having an ordinance that clarifies expectations up front helps developers and project sponsors from the beginning.”

San Francisco planning director John Rahaim thinks that the city is on the right track. He became convinced when he learned that an estimated one billion birds—between 1 and 5 percent of all birds—die each year as a result of colliding with buildings. “Just like we look at other significant environmental issues, we need to look at this one,” Rahaim says.

San Francisco joins other cities in the bird-safe building movement, which is gaining momentum around the country. This past fall, the U.S. Green Building Council introduced LEED Pilot Credit 55: Bird Collision Prevention, with requirements for making buildings more visible to birds as barriers, as well as Pilot Credit 7: Light Pollution Reduction, for eliminating excess lighting at night. Pushed by local chapters of the National Audubon Society, the cities of San Francisco and Chicago (among others) are implementing voluntary nighttime “lights out” programs for downtown buildings during migration periods.

Even the federal government is starting to get on board. Pending legislation—H.R. 1643: the Federal Bird-Safe Buildings Act of 2011, which is now in committee—would direct the Administrator of General Services to incorporate bird-safe building materials and design features into public buildings.