Lately, we’ve been getting questions about tinted glass in bird-safe windows and other glazing applications. For instance, are tinted windows better for birds? If not, what can make tinted glass safe for birds? Do etched markers work as well on tinted glass as they do on clear? Is AviProtek® bird-friendly glass available on a tinted base? (Spoiler – it is.) In this article, we’ll look at the advantages and disadvantages of using tinted glass, especially in bird-friendly projects.

Our thanks to Guernsey architects, Gensler architects, the Shashi Hotel, and Daniel Klem, Jr., Ph.D., D.Sc. for their help in writing this article.

1. Why use tinted glass in windows?

There are many reasons to choose tinted glass windows for your project. Tinted glass can reduce glare and help bring down SHGC, making interiors more comfortable and reducing heating/ cooling load. (Source : ASTM C162) Due to high reflectivity on the outer surface (surface one), tinted glass windows are also effective tools to give privacy to a building’s occupants. This can be an important advantage for projects like schools, gyms, and hospitals, where it’s important to protect the privacy of those inside.

For example, the OVO Athletic Centre in Toronto (formerly known as the BioSteel Centre) uses Optiblue® glass from Vitro to protect the privacy of its occupants, the Toronto Raptors NBA team. Guernsey architects also considered thermal performance, aesthetics, and bird deterrence requirements under Toronto’s Green Standard when choosing the glass for this building. The blue tint combined with a 2” x 2” bird-safe glass pattern on surface 1 helps the project meet Toronto’s bird-friendly guidelines without compromising design, daylighting, or views of the outdoors.

Ovo Athletic Centre Aviprotek Pattern 215 5 WEB Wide

According to Lindsey McBride, Former Associate AIA, Guernsey, “Utilizing [AviProtek acid-etched] bird-friendly glass allowed us to maximize views while achieving our privacy objectives, whereas other bird-friendly design options would have altered our building’s design aesthetics. Building form, exterior shade devices, applied films, and fenestration patterns can be used to alter the bird’s flight path; however, all of these methods result in a loss of natural lighting. Natural light is a necessary feature of high-quality design, and the bird-friendly pattern allows more flexibility in the design without limiting building form or envelope design.”

At the OVO Athletic Centre, tinted glass with bird-safe acid etch was part of a winning design. However, even with all its advantages, tinted glass needs some special considerations. For instance, we’re often asked if tinted glass is a good choice for bird-safe windows. The answer: it can be, when it’s handled right.


If you’re interested in using tinted glass with AviProtek® bird-friendly markers, please reach out to your architectural manager. Our team will be happy to help you select the perfect combination for your next project.

2. Are tinted glass windows better for birds?

Is tinted glass better for birds? On its own, no. In fact, the mirror-like quality of tinted glass can exacerbate the reflective effect on a window. This effect occurs when images of the outdoors are reflected on the surface of the glass, tricking birds into believing that it’s an open space to fly through.

According to Dr. Daniel Klem, Jr., Ph.D., D.Sc., “The level of reflection and its realistic expression on surface one can take place on a clear pane, but any light that’s occurring internal to a room that the pane covers will mitigate that reflection. But in the case of a tinted pane, it’s going to be harder and you’re going to have to use a brighter illumination to mitigate that image on the outside.”

In other words, tinted glass reflects the environment more than clear glass, and it’s more difficult to mitigate these reflections with interior lighting. Therefore, if you’re planning to use tinted glass in windows or other applications that may create reflective conditions, it’s especially important to use first-surface bird-friendly markers and other best practices for bird-safe windows.

3. How do you make tinted glass windows safer for birds?

With tinted glass, as with clear, bird deterrence boils down to making the glass visible to birds. That means interrupting the view through the glass and/or the reflections on its surface. There are several ways to accomplish this, but they’re not all suitable for use on tinted glass. If you’re planning a project with bird-friendly tinted glass, here’s what you need to consider.

Checklist for tinted glass in bird-safe applications

  • First-surface markers
  • High-contrast patterning
  • 2” x 4” or 2” x 2” spacing
  • Durable surface treatment
First-surface placement

We cannot stress this enough: to be most effective, bird-friendly markers must be placed on the exterior surface (surface one) of any glazing unit. This becomes even more crucial on tinted glass, where reflections on the glass surface will block the view of markers on internal surfaces and make it harder to mitigate the reflective effect with interior lighting.

High-contrast markers

Bird-safe glass relies on contrast to make visual markers recognizable against the base substrate. On a dark or tinted glass, for example, light-coloured markers with very little reflectivity will be most effective.

Standardized gloss readings show that the contrast between visual markers and background on bronze-tinted AviProtek® glass is even greater than on our tried-and-true clear AviProtek® glass. That’s because the acid-etched area is pale and matte, while the surrounding tinted glass is significantly darker and much more reflective.

Spacing: 2x4 and 2x2 rules

It’s important to make sure that bird-deterrent markers are closely spaced across the entire surface of the glass. Applicable building standards may require 2” x 4” spacing or 2” x 2” spacing, depending on your project. You can learn more about these standards in our article, The 2×4 rule: The origin and definition

AviProtek® bird-friendly patterns are designed to meet these spacing guidelines. Please see our AviProtek® product options to choose a pattern best suited to your project requirements.


First-surface markers will need to withstand UV rays, dirt, and weathering. Acid-etched markers on tinted glass answer this requirement extraordinarily well. Since they’re etched into the glass itself, these markers will never wear off or degrade.

For more information about the longevity of acid etched markers on glass, please see our article, 5 Ways Acid-Etched Glass Offers More Durability than You Realized.

“Surface number one is a no-brainer. The pattern has to be there, and it has to be contrasting, and the more contrasting, the more effective. I think Walker’s acid-etching technique is again a no-brainer in my mind … It’s just been reinforced by so many experiments over time.”

  • Daniel Klem, Jr., Ph.D., D.Sc.

4. Do bird-friendly glass patterns on tinted windows work?

So, the big question: do acid-etched markers on tinted glass really work?

They do.

In projects across North America, bird-friendly markers on tinted glass are helping to reduce or completely prevent bird collisions.

At the Shashi Hotel in Mountain View, CA, Gensler Architects used blue tinted glass to give the hotel’s façade its striking cerulean colour. This rich hue echoes the look of other Silicon Valley buildings, like the deep blue Google headquarters just around the corner. The hotel also incorporates AviProtek® bird-friendly pattern 211 to make the building safe for local bird life.

Pattern 211 is a vertical stripe with variegated spacing up to 2” wide. In addition to its bird-deterrent properties, the design team liked the visual effect of the pattern, which was previously used in the Oregon Zoo Education Center in Portland. The stripes harmonize with other design elements, including the blue tint of the glass. But does the pattern prevent bird strikes?

Shashi Hotel AviProtek 211 5 WEB

We asked Agustin Sanchez, Director of Engineering at the Shashi Hotel. He told us, “I’m happy to report zero bird strikes. I think it’s safe to say the bird-safe pattern works.”

Gensler’s approach to bird-friendly building follows the lead of nearby cities San Francisco and Palo Alto, as well as California’s voluntary bird-friendly design guidelines. These call for bird-deterrent patterns with 2” x 4” spacing in 90% of glazed areas in the first few stories. San Francisco and Palo Alto standards require treatment in the first 60’ from grade, while the California guidelines recommend treatment on the first 40’ from grade.

What to remember when you use tinted glass in bird-safe applications

As we’ve seen, although tinted glass is not inherently bird deterrent, it can be part of a successful bird-friendly building strategy. When used correctly, bird-friendly acid-etched markers can be as effective on tinted glass as they are on clear.  Furthermore, they can complement the look of coloured glass and contribute to well-lit interiors by offering bird-friendly solutions that don’t interfere with natural light.

The moral of the story: you can absolutely use tinted glass for bird-friendly buildings. Just make sure to do it right.

About Guernsey

Guernsey is a leading provider of design and consulting services. Founded in 1928, Guernsey has developed an impressive base of clients worldwide, including federal, state, and local government; military; utilities; tribal; higher education; Fortune 500 companies; and the oil and gas industry sectors. Guernsey is an employee-owned, multi-discipline firm providing innovative answers for complex projects with engineers, architects, planners, consultants, environmental scientists, designers, analysts, accountants and project managers.

Realize the Guernsey difference at

About Gensler

Gensler is a global architecture, design, and planning firm with 50 locations across Asia, Europe, Australia, the Middle East, and the Americas. Founded in 1965, the firm serves more than 3,500 active clients in virtually every industry. Guided by determined optimism, we believe the power of design can spark positive change and create a future that promotes equity, resilience, and wellbeing for everyone.

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About Dr. Klem

Daniel Klem, Jr., Ph.D., D.Sc. is a Sarkis Acopian Professor of Ornithology and Conservation Biology at Muhlenberg College in Allentown, Pennsylvania. Dr. Klem known for his pioneering research into the mortality of birds due to glass windows. His research has influenced the design of buildings around the world, and he holds several US patents relating to windows design. His recent book, Solid Air: Invisible Killer- Saving billions of birds from windows is a distillation of decades of research and experience in the field.

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About the Shashi Hotel

Shashi Hotel reimagines the Silicon Valley hotel experience as a mix of cutting-edge technology, communal warmth, and impeccable service. From refined guest rooms and sophisticated social areas to an outdoor pool, fitness center and The Emerald Hour Bar, we’ve created the ideal urban retreat for creative types and tech-minded travelers seeking something different.

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