On the left: What birds see from the outside, on the right: what we see from the inside. (click to enlarge)
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Creating Bird-Safe Buildings
By Angela Dean - 13 September 2026 We live in a place with immense natural beauty, which means many buildings incorporate large areas of glass to take in the views. While we are appreciating our natural surroundings, we may be inadvertently causing harm. You may have experienced that sinking feeling of hearing a thud against a window, only to find a motionless bird on the other side. It is estimated that window strikes on homes in Utah account for millions of bird fatalities each year. Fortunately, there are simple ways to avoid this with mindful strategies that create bird-safe buildings. From the outside, our windows can act like mirrors, reflecting the sky and surrounding vegetation. Birds do not distinguish the invisible pane of glass and may fly directly into it. Here are a few methods to consider, from lowest cost to highest cost: Window Screens. If you have screens on the outside of your windows, you are already using a bird-safe strategy. Nice work! Window Decals. It was once thought that placing a bird silhouette on a window would signal to birds to avoid the area. While these can be fun features, they are not effective when used alone. The rule of thumb for effective deterrence is the 2 x 4 rule (2" vertical x 4" horizontal). Most songbirds will not attempt to fly through a gap unless it is larger than their wingspan. Markers must be located on the outside of the glass to be effective. There are a number of products on the market with various patterns to choose from, and they are an easy DIY installation. While these are quite visible from the outside, the views from the inside are minimally impacted. Acopian Curtains. These are cords that are hung from the top of windows and are typically made of 1/8" black paracord that hangs down the full height of the window. These are also easy DIY projects or can be purchased assembled. Again, exterior application is required. One downside is that they may move in the wind and require occasional adjustment. The upside is that some people feel there is less visual disruption to their views. Specialty Glass. Windows can be manufactured with film or fritting that creates a visual pattern of deterrence that is visible to birds but virtually invisible to humans. These products are typically used in high-end custom residential or commercial projects, particularly where large expanses of glass are an important part of the design. I have utilized each of the above strategies across our firm's designs, as well as personally at my home and office, and can attest to their effectiveness. Beyond windows, there are other areas that need attention to create bird-safe places. Vents. Buildings have many vent pipes and openings to the exterior for intake and exhaust. These can be places where birds become trapped or build nests. Take an inventory of where these openings are located and whether they are properly covered or screened. Wire mesh with openings smaller than 1/2" can be added behind vent covers. Note that you should not install mesh over dryer vents, as this may pose a fire risk by trapping lint. The best options in this case are heavy-duty spring-loaded or magnetic damper flaps or cages. Landscaping. While spring may bring motivation to get outside and work on the yard, it is also the time when birds are nesting. Strive to avoid trimming trees between March and August to allow birds time to hatch and fledge. Bird Feeders. When placing bird feeders, the distance from windows makes a big difference. It is best to locate them either less than 3 feet or more than 30 feet away from windows. By placing them within 3 feet, there is not enough distance for birds to build up momentum, so they are more likely to lightly bump the glass. Beyond 30 feet, birds have plenty of space to see the whole structure as an object and avoid it. Go Away, Birds! Sometimes we prefer that birds are seen and not heard—aka, "Stop pecking on my house!" Northern Flickers, in particular, seem to love using buildings as drums to communicate territory or attract a mate, as well as creating cavities for nests. Fortunately, we can implement various strategies to deter and mitigate this behavior. Building with durable materials such as metal, stone, and brick can be impenetrable to even the toughest of beaks. Alternatively, you could install a nest box in the area where they are attempting to create a cavity, giving them what they are looking for. Preserving Dark Skies. Approximately 80% of birds migrate at night, using the stars and Earth's magnetic field to guide them. As such, artificial lighting can disrupt this process, with bright lights leading to confusion that may steer them off course. Large expanses of glass lit from within may also attract birds and increase the likelihood of window strikes. Some methods to mitigate the impact of artificial light include:
Avoiding toxins: While not directly building related, how we treat our landscapes and manage pests directly impacts the survival of birds who come into contact with them. Poison intended for rodents can end up in the systems of birds who consume them, causing mortality through bioaccumulation. In addition, many pesticides and herbicides used in our yards and for agricultural purposes affect the food birds depend on, including insects and seeds. Read labels carefully and avoid products containing neonicotinoids, neurotoxic chemicals found in many common garden and agricultural insecticides. Unfortunately, EPA regulation and labeling of these chemicals can be limited, making them difficult to identify in some products. When pest control is necessary, choosing natural or less-toxic treatments is ideal. Ordinances. On a larger scale, many cities across the U.S. have adopted bird-safe building ordinances. These generally apply to non-residential structures and typically address building size, location, amount of reflective surfaces, threat-factor thresholds, and artificial lighting. Here is a list of current bird-friendly building ordinances: https://bird-friendly.yale.edu/usa-policy-database The next time you take a walk around you home, you may now see things from a bird’s eye view and find opportunities to admire our avian neighbors while keeping them safe. Resources: https://tracyaviary.org/conservation/ https://abcbirds.org/wp-content/uploads/2025/10/ABC-Bird-Friendly-Building-Policy-Toolkit.pdf Angela Dean is Principal of AMD Architecture, was a member of the volunteer City Startup Transition Team and currently serves as Ogden Valley Planning Commission’s Vice Chair. |
