By Liz Brensinger
Birds brighten our yards and our lives year-round. During spring and fall migration, the number of birds, species, colors and songs rises to new heights (pun intended). But migration is an especially fraught time for birds, who are forced to navigate a range of hazards created, unintentionally, by us.
One of the most dangerous is the windows through which we watch them. Birds can’t see glass, but they can see the plants brightening your office or the trees reflected in the glass. Fooled into thinking they can fly right through, a staggering one billion birds a year die from glass collisions in the U.S. alone.*
Fortunately, this is one problem you can solve. The following information, geared especially for architects, builders and developers, can get you started:
- A number of proven tools exist to make buildings safe for birds. Arguably the best of these is bird-safe glass installed during initial construction.
- Bird-safe glass is widely available. A 2025 article in Glass Magazine found that 54% of glass fabricators offer it.
- The American Bird Conservancy website has a product database of bird-safe glass that anyone can use to identify potential vendors. Additionally, staff at ABC will make recommendations based on your specific needs – e.g., desired IGU. Christine Sheppard (CSheppard@abcbirds.org) is ABC’s Glass Collisions Program Director, and Kaitlyn Parkins (KParkins@abcbirds.org) is the Program Coordinator.
- Almost all fatal bird collisions with glass occur at a height of 100 feet or lower, meaning bird-safe glass is recommended for only the first three to seven stories.
- Making a building bird-friendly can sometimes be cost-neutral, according to ABC; at worst, bird-safe glass may raise construction costs by a fraction of 1% of project costs. Bird-safe glass may ultimately reduce operating costs, and installing it during construction is virtually always more economical than a retrofit. Finally, installing bird-safe glass affords the opportunity to avoid adverse publicity resulting from bird deaths and instead generate positive public relations related to sustainability and environmental responsibility.
- Numerous architectural firms have experience with bird-safe design and could potentially act as resources. These include FXCollaborative in New York City, especially FX Principal and Director of Sustainability Daniel Piselli; Gensler; and Jeanne Gang.
For anyone interested in making their own home or building more bird-friendly, options include installing decals or other bird-visible patterns on the outside of windows or even using simple window screens.
At a time when bird populations are plummeting – according to recent research, the U.S. and Canada lost a whopping 2.9 billion birds, or 29% of the population, between 1970 and 2019, due to variables including habitat loss, climate change and collisions with glass – one of the simplest ways to help is by making our buildings bird-friendly. Not only birds, but also our and our children’s futures, stand to benefit.
Green Building United (GBU) supports architects, builders, developers, and community members across the Lehigh Valley who are working toward healthier, more sustainable buildings. We help translate research and best practices like bird‑safe building strategies into practical, locally relevant conversations grounded in real projects and policy contexts.
To stay connected and learn from peers doing this work locally, GBU hosts monthly Lehigh Valley Community meetings to share resources, solutions, and opportunities to improve building performance and environmental outcomes. Anyone interested in bird‑friendly design and other sustainability strategies is welcome to join the Community meetings!
* Research by Muhlenberg College’s Acopian Center for Ornithology; the American Bird Conservancy; Fordham University; Stony Brook University; NYC Bird Alliance