An office building shows reflections of the sky in glass windows.
The evening sky is reflected in the windows at 2150 Shattuck Ave. Hundreds of thousands of birds die in collisions with Berkeley buildings each year. Credit: Ximena Natera, Berkeleyside/CatchLight

Berkeley will soon require major construction projects to use materials that prevent birds from flying into windows and other reflective surfaces — though the regulations don’t go as far as conservation groups had hoped.

The Berkeley City Council approved an ordinance creating those bird safety requirements Tuesday night, while carving out exemptions for smaller residential developments and affordable housing projects, as well as renovations of historic structures, citing concerns about the availability of materials and their extra cost. The ordinance includes a pledge to reconsider those exemptions within the next three years.

Hundreds of thousands of birds die each year from collisions with the glass features of Berkeley houses, apartments and office buildings, according to estimates from the Golden Gate Audubon Society.

Glenn Phillips, the group’s executive director, said conservationists feared there would be far more bird deaths if Berkeley fulfilled state mandates to build thousands of new homes over the coming years without glass regulations. Although it won’t reduce the number of fatal bird strikes, Phillips said, the city’s new ordinance should prevent a catastrophic increase because it will “strongly protect” birds from the new buildings it covers.

“This is a win for birds — I would’ve liked a bigger win, but it’s a win for sure,” Phillips said. “We hope that it will set the stage … for us to come back and say, ‘We need to include more buildings so that we can bring that number down.'”

Berkeley’s ordinance requires that windows and other “high-risk” features like clear balcony railings be made out of materials that pose less of a threat to birds, such as glass that is etched with patterns to help them recognize the window as a solid object, or other treatments rated by the American Bird Conservancy as safer for wildlife.

The mandate applies to new housing and commercial construction, as well as renovations, expansions or other work on existing structures requiring a building permit; simple window replacements aren’t affected.

Residential buildings smaller than 10,000 square feet of gross floor area or 35 feet in height are mostly exempt from the requirements, though they would have to use bird-safe materials on any high-risk features. Projects where at least half of units are affordable and historic properties are fully exempt.

Trees and street lamps are reflected on the first-floor windows of the Residence Inn by Marriott in downtown Berkeley.
Trees and street lamps are reflected on the first-floor windows of the Residence Inn by Marriott in downtown Berkeley. The building, which opened in 2021, includes bird safety features. Credit: Ximena Natera, Berkeleyside/CatchLight

The ordinance also won’t affect projects currently under construction or in the city’s approval pipeline — it will apply to new development proposals submitted from late July onward. The mandate for renovations will take effect in 2025 for commercial projects and 2028 for residential ones.

Environmental groups have pushed Berkeley for years to adopt bird safety regulations, noting several surrounding Bay Area cities already have such ordinances, and tens of millions of birds pass through the region on their migrations. Dozens of people who supported safety regulations attended Tuesday’s City Council meeting, including several young activists who described the effort to protect birds as a matter of safeguarding the environment for future generations.

“I don’t want any more birds dying — they’re part of our ecosystem,” said Kameron Winchester, a speaker from the group Youth vs. Apocalypse.

But while council members said they want to protect wildlife, several expressed concern about imposing the requirement to use more expensive bird-safe windows on home renovations or smaller housing projects such as backyard cottages and duplexes.

Berkeley has been loosening zoning rules and other regulations in an effort to encourage property owners to build those kinds of projects as a solution to the housing crisis, and Mayor Jesse Arreguín said he worried smaller-scale builders might have a harder time absorbing the extra costs than bigger apartment developers. Critics also argued it could be difficult to find bird-safe features for smaller projects, pointing to a survey by city staff who contacted 13 Berkeley-based building materials retailers and found non carried the products.

“I am concerned that the materials are not widely available, and the cost for smaller projects could negatively affect the financial feasibility of those projects,” Arreguín said. “Either things aren’t going to get built, or they’re going to have to pay a lot more.”

Supporters of tighter bird safety regulations argued that glass represents a small piece of any construction budget, and builders could offset higher costs by designing smaller windows. They also contend Berkeley’s regulations could have pushed suppliers to make those materials more widely available.

There were competing proposals for bird safety regulations before the City Council on Tuesday. Councilmember Kate Harrison put forward a more stringent ordinance, based on legislation recommended by Berkeley’s Planning Commission, that would have applied the mandate to smaller and affordable projects starting in 2025. Councilmembers Rashi Kesarwani and Susan Wengraf proposed looser regulations that, among other differences, would’ve exempted those projects and only applied bird-safety requirements to larger pieces of glass.

During Tuesday night’s discussion, Arreguín proposed what he described as a “compromise” that amended Harrison’s proposal to exempt smaller and affordable housing projects, as well as historic structures; the council approved that ordinance unanimously.

“We have to start somewhere, and we’re starting in a really good place,” Harrison said as the council prepared to vote for the ordinance. “But I don’t want to assume that these are going to be the costs forever — at some point, this will become the standard.”

A bird flies through downtown Berkeley. A building window is in the background.
A bird flies through downtown Berkeley. Supporters say the city’s new ordinance won’t reduce the number of bird collisions and deaths, but could prevent them from increasing as the city pushes for more construction. Credit: Ximena Natera, Berkeleyside/CatchLight

Nico Savidge joined Berkeleyside in 2021 as a senior reporter covering city hall. Born and raised in Berkeley, he got his start in journalism at Youth Radio as a high-schooler in the mid-2000s. Since then,...