We've all seen them: dead birds on the ground beside a glass building. Or maybe you've heard the unmistakable sound of a bird crashing into your window while working at your desk. It's sad, of course. Birds can't distinguish glass as a solid barrier and perceive what the glass reflects, such as vegetation, trees, or sky, to be real, so they fly toward it.
As high-rise cities expand, birds dying or suffering from injuries from crashing into glass buildings, as often seen on commercial real estate, is becoming too big a problem to ignore: Between 600 million and 1 billion birds die this way each year in the United States. Developers should be aware of new bird-friendly glass ordinances some cities are adopting.
New York City's ordinances
New York City is on a bird migration path, and about 200,000 birds die each year in this city alone from flying into buildings there. To make matters worse for birds, many glass buildings in The Big Apple are required to have green spaces on the rooftops of the glass buildings. This only serves to attract birds, the effect of which is even more bird deaths as they fly away from the green space and into the building or a neighboring glass building.
As a result of all the carnage, NYC passed a bill, which went into effect December 2020, making buildings safer for birds. There will need to be patterned glass or other such bird-friendly materials that would deter birds on up to 75 feet above grade of new or altered glass buildings.
Note that Mountain View, California, also passed legislation that all new buildings and altered buildings must use bird-friendly materials for 90% of the facades that go up to 60 feet. And other municipalities have some mandatory ordinances in place as well.
Ways to incorporate bird-friendly design
For existing buildings, one idea to help save birds is to use a technique called "fritting," or applying ceramic dots or lines to glass. In one experiment, the Jacob K. Javits Convention Center in Manhattan, one of the biggest death traps for birds, was renovated using fritted glass at a cost of $1 billion over five years. Expensive, but it worked: Bird deaths were reduced 90%.
Existing buildings can also be retrofitted to be bird-friendly through other methods. Netting and screens are the most cost-effective measure to take, although maybe not the most attractive. Window film, shutters, and grills cost more but might look better than netting and screens. Replacing the glass is the most expensive method, but it will be attractive and long-lasting, with minimal upkeep.
Lighted glass buildings at night
Although most birds migrate during the day, some fly at night, and buildings that are lit up at night disrupt bird flight patterns. So unless being lit up at night is for safety reasons, Leadership in Energy and Environmental Design (LEED) recommendations are to shut off lights from midnight to 6 a.m. (To get a possible LEED point for a building, there are bird collision deterrence guidelines.)
Why the fuss over birds?
Saving birds isn't some crazy overreach by environmental activists. We need birds, as they consume insects, control the rodent population, reduce damage to crops, pollinate plants, and disperse seeds. And consider this pursuit: bird watching. This fast-growing leisure time activity has become a $40 billion industry that creates many jobs.
The Millionacres bottom line
Since folks have been studying the issue, they've found that patterned glass needs to cover only 5% to 7% of the glass surface to work. If New York City, with all its high-rises, can start producing bird-friendly buildings, developers and investors can likely expect other major cities to follow suit as people are taking an increased interest in sustainable design.