Bird-Safe Glass in Architecture  

Photo courtesy of Philip Castleton Photography Inc.

The Boulevard Club in Toronto features ultra-clear, bird-friendly, and high-performance glass that balances transparency, safety, and solar control. The architect is Teeple Architects in Toronto.

Bird collisions with glass pose a serious threat to wildlife, impacting both common and endangered species. Architects and the AEC industry can play a vital role in reducing this hazard through bird-friendly design. This course explores why buildings are dangerous to birds, how glass characteristics and patterns can prevent collisions, and which advanced glazing solutions are available. Participants will also learn specification strategies that align with LEED Innovation credits. By incorporating bird-safe materials, architects can protect wildlife, promote sustainability, and create healthier environments for both people and ecosystems.

WHY DESIGN GLASS AND BUILDINGS TO SAVE BIRDS?

While glass defines much of contemporary architecture, it is also a major source of bird mortality. Research from the American Bird Conservancy (ABC) estimates that more than a billion birds die annually in the U.S. from glass collisions, and the actual number may be even higher. These collisions affect a wide range of species—from common backyard birds to endangered populations—and virtually any glass-covered structure, large or small, can present a risk. Understanding these hazards is the first step toward designing safer buildings.

As ABC notes, “about 25 percent of species are now on the U.S. Watch List of birds of conservation concern, and even many common species are in decline. Habitat destruction or alteration of both breeding and wintering grounds remains the most serious man-made problem, but collisions with buildings are second only to domestic cats as direct fatality threats.”

Why should we care about protecting the avian wildlife population? Beyond their role as long-standing cultural symbols and a source of beauty, birds perform critical ecological functions. They eat insects and rodents, thereby controlling their populations; pollinate plants and disperse seeds; and limit the transmission of mosquito-borne illnesses.

Like all animals, birds are driven to meet essential biological and behavioral needs—to find food, shelter, mates, and community. Unlike most species that remain close to the ground, birds are in constant motion, swooping between trees in daily foraging or traveling thousands of miles during migration. These instinctive patterns place them directly in the path of built structures. Transparent and reflective glass creates the illusion of open sky or accessible habitat, tricking birds into fatal collisions. That misperception is at the core of the problem—and one that architects and designers are uniquely positioned to solve.

Glass and Bird Safety

Glass is hazardous to birds when:

• It is located on common flight or migratory paths
• It is transparent
• It resembles the natural environment

Anyone who has walked into a freshly cleaned glass door knows that transparent glass is also difficult for humans to see. But we’ve learned to pick up on visual cues like dirt on glass that alert us that it is there. Birds have poor depth perception and typically don’t ever encounter glass until they’ve hit it traveling at high speed.

Image courtesy of U. S. Fish & Wildlife Service

The four main migratory paths of North American birds.

The image shows the four main migratory paths of North American birds. Birds fly through cities to get to their migratory destinations, and they’re often forced to rest in city parks or tree-lined streets rather than their more native habitat. As cities rapidly develop and buildings are constructed across the skyline, it becomes increasingly difficult for birds to avoid glass buildings, which now make up the majority of architectural design in urban areas.

The American Bird Conservancy notes, “Advances in glass technology and production since the mid-twentieth century have made it possible to construct skyscrapers with all-glass walls, homes with huge picture windows, and miles of transparent noise barriers on highways. There has been a general increase in the amount of glass used in construction, and the amount of glass on a building is the best predictor of the number of birds it will kill, which is why bird-friendly design is becoming recognized as part of sustainable design, required increasingly by legislation across North America.”

Commercial building owners and tenants often beautify the interiors of buildings with plants, bushes, trees, and other natural vegetation. When birds are faced with highly transparent glass that is not visible, they mistakenly think they can fly into these trees and plants to perch inside buildings.

Reflective Glass: Likewise, birds attempt to fly into trees reflected on the glass, mistaking them for their natural environment. Instead, they are met with a curtain of glass.

Fly-through Conditions: When there are see-through areas of a building, such as glass sky bridges or corner windows, birds believe they can fly through these transparent building areas.

Glass in Nature: Glass environments that look like their natural habitat can put birds at risk as well. Examples are glass located near green roofs and walls.

Backlit Glass at Night: Stronger indoor lighting during low-light hours can also make glass imperceptible to birds. The ABC says, “The amount of light emitted by a building is a strong predictor of the number of collisions it will cause, more so than building height.” They also note that interior lighting should be turned off at night if not in use. This strategy minimizes light escaping through windows during night operation. Outside lighting should be shielded and directed to reduce attraction to night-migrating or nocturnal birds.

GLAZING AND AEC ROLES IN BIRD-FRIENDLY GLASS

Photo courtesy of Rick Keating

The Oregon Zoo Education Center in Portland earned a LEED Platinum certification. It includes bird-friendly glass, acid-etched on a high-performance solar control low-e coated glass. The architect is Opsis Architecture in Portland, Oregon.

Architects and building owners play an increasingly important role in advancing bird-friendly design and mitigating collision risks, particularly in regions where codes and sustainability frameworks prioritize this issue.

Designers can deter bird collisions by incorporating effective glazing solutions into their projects. By specifying proven materials and technologies, architects create bird-friendly buildings that preserve aesthetics, function, and natural light.

What Is Bird-Friendly Glass?

Glass can confuse birds due to its transparency and reflectivity. Bird-friendly or bird-deterrent glass features optical markers, such as lines or dots, that are visible to birds and help them avoid collisions. These patterns can be on the glass surface or embedded in a laminate. Patterns are designed to maximize visibility to birds but minimize visibility to humans.

ABC notes, “If birds see reflections of trees or sky in the glass, they perceive it as an open space in which to fly. By etching the exterior, also called the ‘first surface’ of the glass, its reflective quality is broken up, and the illusion of open space is removed. Similarly, the etching disrupts the uniform transparency and alerts birds to the presence of the glass.”

Bird-Friendly Building Codes

Bird-friendly building codes have been enacted in several North American states and provinces, including California, Illinois, Maine, Maryland, Minnesota, New York, Oregon, Virginia, Washington D.C., Wisconsin, Alberta, British Columbia, and Ontario.

For example, the policy in San Francisco dictates that “Bird-safe glazing treatment may include fritting, netting, permanent stencils, frosted glass, exterior screens, physical grids placed on the exterior of glazing, or UV patterns visible to birds. To qualify as Bird-Safe Glazing Treatment, vertical elements of the window patterns should be at least 1/4 inch wide at a minimum spacing of 4 inches or have horizontal elements at least 1/8 inch wide at a maximum spacing of 2 inches.”

Bird-Friendly Glass Rating Systems

Photo courtesy of Philip Castleton Photography Inc.

The OVO Athletic Centre in Toronto, Ontario, incorporates bird-friendly acid-etched tinted glazing with solar control low-e glass to balance collision deterrence, daylighting, and energy efficiency. Architects: Guernsey Architects (lead architect), Baldwin & Franklin (supporting architects).

Bird-friendly glass rating systems include:

• San Francisco’s Standards for Bird-Safe Buildings
• California’s A5.107 Bird-Friendly Building Design
• National Glass Association’s Best Practices for Bird-Friendly Glazing Design Guide
• Canada’s CSA A460:19 Bird-Friendly Building Design Standard
• Toronto Green Standard v4
• New York City’s Local Law 15 of 2020: Bird Friendly Building Design

Architects practicing in the locations mentioned above should take particular care to stay ahead of code requirements and new legislation. Still, architects everywhere should understand the importance of bird-friendly glass and the advanced architectural glazing options available on the market.

Note: Bird-friendly glass codes, requirements, and legislation can be dictated by local jurisdictions. Please consult specific regulations for your project’s location. The Yale Bird-Friendly Building Initiative created a database of U.S. Bird-Friendly Building Policies at https://bird-friendly.yale.edu/usa-policy-database.

Assessing Bird-Friendly Glass

To assess bird-friendly glass, various deterrents are tested, and the ABC assigns a Threat Factor (TF). This method assigns scores to measure the effectiveness of visual marker patterns in deterring birds in a controlled test environment.

Threat Factor scores are assigned to provide a relative measure of how well materials with patterns of visual markers cause bird avoidance. The lower the Threat Factor, the better the material is at reducing bird strikes.

The tunnel test is a method for assigning Threat Factor scores that provide a relative measure of how well materials with visual marker patterns cause avoidance by birds in this standard, controlled test environment. 

In a test flight, a bird flies down a completely dark space, toward light at the far end, where side-by-side panels of glass appear to offer exit routes. One is clear and unmarked glass, while the other has the pattern of visual markers being evaluated. A net stops the birds before they can hit the glass.

The American Bird Conservancy defines ‘bird-friendly’ or ‘bird deterrent’ materials as those with a Threat Factor of less than 30, indicating they can reduce bird collisions by roughly 50 percent or more. However, it’s important to note that the Threat Factor does not scale in direct proportion to collision reduction. For instance, a material with a Threat Factor of 15 does not guarantee a 75 percent reduction in collisions; rather, it simply indicates stronger deterrence compared to a higher Threat Factor.

The 2 by 4 Rule

Marking patterns, like lines or dots, in a 2-inch high by 4-inch wide spacing can help most bird species detect an impassable medium, at a distance of at least one 3.28 feet so they change their flight path in time to avoid a collision. Glass that meets this requirement can help deter up to 90 percent of bird collisions.

Patterns applied to the exterior surface of glass via etching, UV coatings, or other means help to combat glass reflection and transparency. The etched patterns alert birds to the presence of the glass so they can change course before striking it.

The Importance of Marking Patterns: Etching lines or dots in spaces 2 inches high by 4 inches wide can help most bird species detect an impassable medium at a distance of at least 3.3 feet. Lines or dots spaced 2 inches high by 2 inches wide can help smaller bird species avoid glass collisions. The tighter marking patterns have a lower Threat Factor.

Where Do Bird-Visible Markings Work Best?

According to the ABC, “Most clear glass made in the United States transmits about 96 percent and reflects about 4 percent of light falling perpendicular to the outside surface. Light on the inside of the glass is also partly reflected and partly transmitted. The relative intensities of light transmitted from the inside and reflected from the outside surfaces of glass, combined with the viewing angle, determine whether the glass appears transparent or mirrors the surrounding environment.” Because the optical properties of glass are so dynamic, patterns applied to the outer surface are most effective at deterring bird collisions.

CHARACTERISTICS OF AND OPTIONS FOR ADVANCED BIRD-FRIENDLY GLASS

Photo courtesy of Jim Cunningham

The Hugel Welcome Center in Markle Hall on the Lafayette College campus in Easton, Pennsylvania, features vacuum insulating glass units with solar control low-e glass on the second surface and bird-friendly patterned glass on the exterior lite. The acid-etched pattern enhances visibility to birds and helps prevent collisions. The architect is ALMA Architecture, LLC, in Philadelphia.

There are several bird deterrent glass technologies currently available to specify on projects without impacting visible light transmittance (VLT) or solar heat gain coefficient (SHGC).

By combining bird-safe glass with solar control low-e glass products, you can achieve both bird-friendly etching and solar performance.

First surface etched markings contrast the reflection on the outermost surface of the glass, making markings visible at many bird-approach angles. There are two methods of achieving etched glass: laser and acid.

Laser-etch and acid-etch technologies can be slightly visible or mostly invisible depending on lighting and background conditions.

Each manufacturer has its proprietary process for acid-etching a glass surface. One manufacturer uses a controlled solution of hydrofluoric acid to uniformly etch the surface of the glass. Rigorous process control ensures a repeatable, uniform appearance.

Variances in opacity within a sheet will be indistinguishable to the naked eye when viewed under normal viewing conditions. This surface treatment does not have any significant impact on the light and performance values of an insulating glass unit (IGU). Therefore, values will be similar to units without patterned acid-etched glass.

Options for Acid-Etch Glass

There are two common options for bird-friendly acid-etched glass. The first is acid-etched markers on the exterior (first) surface of either clear or ultra-clear monolithic glass. This full-surface treatment achieves a muted finish on the building’s exterior facade. Second, acid-etched markers can be applied on the exterior surface of an insulating glass unit (IGU), which is preferred to prevent bird collisions, with a solar control, low-e coating applied to the interior (second) surface, which is ideal for optimizing energy efficiency.

Benefits of Laser-Etch Technology

Laser etching provides a more environmentally conscious alternative to traditional glass etching methods. This non-caustic process minimizes the use of potentially harmful chemicals while achieving a similar effect. Because it involves fewer production steps and shorter-distance transportation, laser-etched glass also generates a lower carbon footprint.

A laser beam creates patterns or markings on the glass surface, often in the form of dots or lines. The laser-etched markings are typically clear and precise, allowing for a high level of visibility for birds while maintaining a relatively clear view for humans. The laser etching process creates a more precise, durable, and sustainable solution, while acid etching creates a frosted or translucent finish.

Laser-etched bird-safe glass is a first-surface marking designed to meet even the strictest building codes and is effective even for birds such as hummingbirds, pigeons, and birds of prey that don’t see ultraviolet (UV) coatings as well. Laser-etched glass can be manufactured with or without a low-e coating.

First-Surface Laser-Etch and Acid-Etch

Characteristics of first-surface laser-etch and acid-etch include:

• Lower perceptibility to humans
• Color appears slightly frosted; light passes through
• Multiple pattern options
• Perceptible to many bird species
• ABC Certified
• Highest energy efficiency when paired with a low-e coating on the second surface

Note: Substrates and sizes differ per manufacturer.

Acid-etched low-e glass patterns can be applied as vertical, horizontal, or organic lines, as well as various decorative dot patterns to suit your aesthetic.

Here are some of the readily available laser-etch and acid-etch technology patterns.

Image courtesy of Vitro Architectural Glass

Laser-etch and acid-etch technology patterns.

• 2-inch x 2-inch In-line
• 2-inch x 2-inch Shift
• 2-inch x 4-inch In-line
• 2-inch x 4-inch Shift
• 2-inch x 2-inch Randomized Squares
• 2-inch x 4-inch Randomized Squares
• Vertical Lines
• Organic

Note: Custom patterns can also be produced. Ask the manufacturer for available options.

Testing Laser-Etched Glass

Laser-etched glass has been evaluated using several standardized ASTM tests. Preliminary findings are summarized below:

Stain Resistance – ASTM C1378-20: Ceramics (in this case, glass) were exposed to staining agents and then cleaned at various levels to measure stain removal difficulty. Result: No difference between etched and unetched glass.

Scratch Resistance – ASTM C501-21 (Taber Test): Glass was intentionally scratched using a Taber machine to assess resistance. Result: No difference in scratch resistance between etched and unetched glass.

Weathering – Accelerated Aging: Glass was exposed to high heat and humidity to simulate long-term aging. Color and gloss of the etched dots were measured periodically. Result: Negligible change observed.

Strength – ASTM C158-02: Measures strength differences between etched and unetched glass under load. Result: Negligible difference observed.

Understanding Ceramic Frit

Ceramic frit is commonly used to reduce the risk of bird collisions with glass. It consists of finely milled glass blended with pigments to achieve the desired color. The mixture is first applied to the glass surface and partially cured. During final processing, the coated glass undergoes tempering or heat strengthening, which permanently fuses the frit into the surface.

Because the coating becomes part of the glass, ceramic frit is highly durable, resistant to scratching, and helps control glare and solar shading. It is most often applied to the second surface of monolithic glass or the fourth surface of an insulating or laminated unit. However, first-surface applications are also available and are particularly effective in bird-friendly designs.

A glass fabricator may or may not have the capabilities or willingness to produce first-surface ceramic frit coatings. Ceramic frit is not optimized for the first surface of IGUs, and first surface ceramic frit coatings may have a less robust warranty than ceramic frits used on other glass surfaces, like second or third. Designers and specifiers should consult with a glazier or fabricator to inquire about their production capabilities and the details of any warranty.

Be aware that if specified, a first surface ceramic frit generally does not share the same substrate as a low-e coating. Therefore, when ceramic frit is placed on the first surface, the low-e coating must be placed on the third surface, potentially compromising energy performance. While ceramic frit is commonly used to satisfy bird-safe glass requirements, laser- or acid-etched visual markers are generally more effective when optimized for energy efficiency.

First-Surface Ceramic Frit: First-surface ceramic frit has characteristics that differ from those of laser- or acid-etched glass. It is more perceptible to humans due to the high contrast of the material and the outermost surface of the glass. The color commonly varies from white to gray to simulate acid-etch, and light typically does not pass through. Multiple pattern options are available, but specifiers should verify the Threat Factor for each, as it can vary. Plus, it is perceptible to many bird species and is ABC certified.

Second-Surface Ceramic Frit: If second-surface ceramic frit is specified, it generally does not share the same surface as a low-e coating for most glass fabrication. In the case of a ceramic frit pattern specified on the second surface, the low-e coating will be placed on the third surface. It may be proposed as an option to any specified bird-friendly product. Specifiers should evaluate the performance and aesthetics of moving a low-e coating to the third surface. Second-surface ceramic frit is ABC-certified. There are specific considerations when specifying second-surface ceramic frit. Strong reflections can reduce pattern efficacy by concealing the visual markers during part or all of the day, if the markers are on an inside surface of the glass. And the surface of the glass appears more reflective at angles other than the direct line of sight.

Note: A ceramic frit ink exists that can be applied to a manufacturer’s low-e coating to achieve a bird-friendly pattern. This technology may be limited to glass fabricators that carry the manufacturer’s low-e coated glass and possess frit printing capabilities.

Second-surface ceramic frit may have a strong contrast to the outside world when the light is brighter outside. This may be due to light not passing through the frit material. A designer may want to choose the frit color after viewing it in different lighting and background conditions.

Why Outside Patterns Work Best

Clear glass in the U.S. typically transmits about 96 percent of perpendicular light and reflects about 4 percent. But at sharper viewing angles (more than 70 degrees), reflection can rise to 50 percent. Because glass reflects both external light and internal conditions, its appearance changes with angles—sometimes transparent, sometimes mirror-like.

This shifting optical behavior means that patterns applied to the outer surface of glass remain visible in more conditions, while interior patterns may disappear or blend into reflections. For bird-friendly design, exterior-surface treatments are therefore more effective.

UV Coatings

Photo courtesy of Scott Witalis

This building in Pittsburgh, Pennsylvania, features bird-safe glazing with surface treatments that increase visibility to birds while maintaining transparency and energy performance for occupants.

UV coatings are another option for bird-friendly glass. They have lower perceptibility to humans but are perceptible to many bird species, like songbirds. However, other species such as raptors, kingfishers, hummingbirds, and pigeons are less sensitive to UV.

Although UV Coatings are mostly clear and “invisible,” color variation in the green and purple range can be detectable. UV coatings can also collect moisture and become very apparent over time. Viewing projects with this technology helps ensure it fits expectations.

Some UV coating technologies require laminated applications within insulating glass units, which adds to the costs. Other UV coating technologies do not need to be laminated when used in an insulating glass unit. An IGU with a laminated outboard lite with a low-e coating on the fourth surface may be the more expensive IGU construct.

Laminated Glass

Laminates are highly perceptible to humans. The color appears silver-reflective, and light commonly cannot pass through the markers. It is available in both 6-millimeter and 9-millimeter marker sizes. It is perceptible to many bird species. Check with the manufacturer to determine ABC certification 

Another downside of laminates is the difficulty in aligning patterns from one window to an adjacent window. In addition, an IGU with a laminated outboard lite with a low-e coating on the fourth surface may be an expensive IGU construct. In that case, a low-e coating can be placed on the fifth surface rather than the fourth surface.

Post-Installation, Field-Applied Markers

Those seeking to retrofit existing building glass to be more bird-friendly may wish to use field-applied markers that are applied after the glass is installed in the building opening. Like laminates with sequins, field-applied markers are perceptible to many bird species but are also highly perceptible to humans.

The color appears as various colors or reflective. The markers may appear uneven when installed without a template or pre-measured film. Check with the manufacturer to determine ABC certification.

When considering the cost of bird-friendly applications, laser-etch technology has the largest usable glass sheet sizes at:

• 130 inches x 204 inches
• 130 inches x 240 inches

Oversized or Titan™ glass sizing allows more glass panes to be cut and greater optimization. Be sure to discuss the opening size design with the project-bidding fabricators to optimize panel usage and minimize waste. Too much waste may make it into the glazing quote/bid.

Cost-Reducing Considerations

Pattern selection may also lead to better sheet usage and possibly better pricing. “In-line,” “Shifted,” and “Lined” patterns may have to be aligned when used in adjacent glazing for best visual appeal, but “Randomized” patterns do not need to be aligned in adjacent glazing.

SPECIFICATION CONSIDERATIONS FOR ADVANCED BIRD-FRIENDLY GLASS

When specifying advanced bird-friendly glass, architects must evaluate key performance and design factors—including reflectance, uniformity, height placement, tint, and rail applications—while aligning with LEED requirements for bird collision deterrence.

Exterior Reflectance

Exterior reflectance is a key consideration when specifying bird-friendly glass. Insulating glass units should have an exterior reflectivity of 15 percent or 16 percent to enhance bird avoidance. An elevated exterior visual reflectivity can reflect a bird’s natural habitat, which may lead to increased bird collisions. Under certain conditions, transparent glass on buildings can act as a mirror, reflecting the sky, clouds, or nearby habitats that attract birds.

Note: The ABC will not test any bird-deterrent markings on surfaces other than the first surface if the exterior reflectivity is greater than 15 percent.

Height Considerations

Glass markings are typically placed at the height of mature trees, about 40 to 60 feet above ground, to align with common bird flight paths. In some areas, local regulations may require bird-deterrent markings at heights of up to 100 feet.

Glass Uniformity

When low-e coatings and glass substrates are consistent across all building floors, visual uniformity and the highest energy efficiency are achieved. Achieving glass uniformity using bird deterrent technologies can be a challenge. Here are some tips to achieve a consistent look from the ground floor up to the top floor:

• Use glass with a similar low-e coating throughout all building floors.
• Ensure that glass substrates are similar throughout all floors.
• Specify low-e coatings on similar surfaces throughout all building floors. This can also be beneficial for energy efficiency.
• An example of this could be:
• Floors one through three have a bird-deterrent marking on surface number one of clear glass and a double-silver low-e coating on surface number two of the glass.
• Floors four through 11 have a similar double-silver low-e coating on surface number two of clear glass.

Note: If a low-e coating is ever placed on surface number three on floors one through three (using a bird deterrent on surface number one), and floors four through 11 have the low-e coating on surface number two, the overall building may not have a uniform color appearance. This is assuming the same low-e coating is used throughout the building facade.

Tinted Glass Applications

Tinted glass may reflect the environment more than clear glass, depending on the added coating’s reflectivity; however, it helps achieve privacy and energy efficiency goals. It’s important to use first-surface bird-friendly markers to create an elevated contrast between the tinted substrate and the marker. Certain types of coated, tinted glass may reflect the environment more than clear glass, yet they help achieve both privacy and energy efficiency goals.

Laminated Glass in Railings

Photo courtesy of Philip Castleton Photography Inc.

The OVO Athletic Centre in Toronto, Ontario, includes bird-friendly acid-etched glass on tinted substrate, combined with solar control low-e glass. Architects: Guernsey Architects (lead architect), Baldwin & Franklin (supporting architects).

Glass railings can appear as “fly-through” areas to birds. Applying a bird-deterrent option can reduce bird strikes.

A UV coating will be featured on the first surface of a laminated construct. Ceramic frit coatings can be featured on exterior surfaces of a laminated construct, like the first surface. Still, they will commonly be placed on the second or the third surface in contact with the laminate. Finally, laser-etch and acid-etch technologies will be featured on the first surface, not the surfaces in contact with the laminate.

If code allows, tempered glass may be used instead of laminated glass on railings. Bird-friendly options for tempered glass include ceramic frit, laser- or acid-etched, and, less commonly, UV coatings.

LEED Credit Overview

Bird-friendly coatings are a critical consideration for mitigating collision risks across all building types, and they take on added significance in projects pursuing LEED certification.

The following materials and design parameters align with the requirements of the LEED Innovation credit for “bird collision deterrence.”

One point is possible under LEED BD+C: New Construction v4.1, in the category of Innovation: Bird Collision Deterrence. The intent of this credit is to reduce bird injury and mortality from in-flight collisions with buildings.

Building developers who wish to earn this LEED credit must quantify the threat level to birds posed by various materials and design details. These Threat Factors are used to calculate an index, or weighted average, representing the building’s facade; that index must be below a standard value to earn the credit. The index is intended to provide wide latitude in creating designs that meet the criteria. The credit also requires adopting interior and exterior lighting plans, as well as post-construction monitoring.

LEED Credit Requirements

To earn the LEED Innovation credit for bird collision deterrence, exterior lighting must comply with two sets of requirements: 1) meet the uplight and light trespass limits outlined in the LEED SS Credit for Light Pollution Reduction, and 2) satisfy the ‘Building Facade and Site Structures’ criteria.

You must develop a building facade and site design strategy to make the building and site structures visible as physical barriers to birds. For the purposes of this credit, “bird-friendly materials” include glazing that incorporates physical signals to birds created by fritting and UV coatings, non-glazing, opaque and non-reflective materials such as concrete, glazing behind qualifying sunshades and screens, and glazing to which materials such as qualifying window films have been applied.

If all materials on the building have a Threat Factor of 30 or below, the project is exempt from the building facade requirements. Otherwise, you need to calculate the Bird Collision Rating using instructions found on the LEED website. All other structures on the site, including, but not limited to, handrails, guardrails, windscreens, noise barriers, gazebos, pool safety fencing, bus shelters, band shells, etc., must be constructed entirely of materials with a threat score value of 30 or less.

LEED Documentation

To earn the LEED Innovation credit for Bird Collision Deterrence, project teams must provide clear and complete documentation that demonstrates compliance with the credit requirements. Submissions begin with the Bird Collision Rating Spreadsheet, which quantifies the overall threat posed by the facade. If any of the specified materials have a Threat Factor greater than 30, the spreadsheet is required to calculate a weighted average rating for the building.

Design drawings must also be included, such as plans or elevations that clearly identify the placement of glazing, frit, etching, coatings, shading devices, or other materials incorporated to reduce collision risk. These drawings should correspond to the specification sheets submitted for each product, outlining material type, finish, surface location, and manufacturer details.

In addition, the credit requires documentation of lighting strategies. An exterior lighting plan must be submitted showing site boundaries, luminaire locations, lighting zones, and control measures. The plan should demonstrate compliance with uplight and light trespass limitations. A luminaire schedule is also necessary, listing uplight ratings, programmed nighttime shut-off times for a typical day, and provisions for manual override controls. Together, these documents ensure that both facade design and lighting strategies contribute to a safe and bird-friendly building environment.

CONCLUSION

Birds are vital to healthy ecosystems, supporting pollination, seed dispersal, and natural pest control, yet more than a billion die each year from collisions with glass in the built environment. For architects and designers, this reality highlights the importance of mitigating glazing-related risks while still delivering buildings that are functional, efficient, and visually appealing.

The architecture and construction industries have a unique role to play in advancing solutions. Glass manufacturers now produce bird-friendly glazing that incorporates markers, coatings, and other technologies proven to reduce collisions without sacrificing transparency, daylighting, or aesthetics. These materials not only help safeguard wildlife but also contribute to sustainable, resilient design practices.

Equally important, architects and specifiers can align their design decisions with LEED criteria. Careful product selection and documentation allow projects to pursue the Innovation credit for “bird collision deterrence,” ensuring ecological responsibility is recognized as part of broader environmental performance.

Advanced glazing strategies—whether addressing exterior reflectance, achieving glass uniformity, or selecting the right tinted and laminated glass—are most effective when considered early in design. For optimal results, project teams should consult directly with their glass manufacturer to identify the best products and configurations tailored to their project goals.