The bird friendly glass pyramid of the National Aquarium in Baltimore is a defining feature of the city’s skyline. With its 684 glass panels forming a commanding structure, it’s been a symbol of the Aquarium and the city itself since its original construction in 1981. However, by the late 2010s the original glass panels were approaching the end of their useful life. In early 2022 the Aquarium announced their plan to address the problem with a renovation that would not only restore the pyramid’s visual appeal, but also improve energy efficiency, daylighting, bird safety, and comfort for occupants.
This case study tells the story of the pyramid’s renewal, including the addition of Walker Textures® low-e coated acid-etched glass. Our thanks to Seonhee Kim of Design Collective and Ken Howell from the National Aquarium for their input about the project process and final results!
Project Credits
- Architect: Design Collective
- Fabricator: Oldcastle BuildingEnvelope Wright City
- Glazing Contractor: Super Sky Products Enterprises, LLC
- Aluminum finishing by Linetec
- Starphire Ultra-Clear® glass and Solarban® 60 low-e coating provided by Vitro Architectural Glass
- Photography: Federal Hill Photography, LLC
We collaborated with Super Sky and Linetec on an article by Max Perilstein entitled, “The Inside Story of the Skylight Repair and Renovation at the National Aquarium in Baltimore, Maryland”. You can find that article at Repair and Renovation – Supersky.
Meeting Modern Standards: Glass that Does it All
The project presented several challenges. For one, the new glass panels needed to meet modern environmental standards that weren’t on the radar when the pyramid was originally built. The glass had to prevent bird collisions, manage the indoor climate in an energy-efficient way, and ensure optimal daylight transmission for the plants in the Upland Tropical Rain Forest exhibit.
Walker Glass helped Design Collective meet these goals by supplying acid-etched glass with a full-surface Opaque finish on surface one and a Solarban® 60 low-e coating from Vitro on surface two. This combination of etch and low-e technology, first introduced in 2020, provides unique features.
The National Aquarium is among the first architectural projects to incorporate this type of glass. The acid-etched surface on the exterior reduces glare and prevents bird strikes by making the surface visible to birds, while the low-e coating optimizes energy performance by regulating heat transfer. A Starphire Ultra-Clear® substrate from Vitro helps boost light transmittance into the pyramid, creating an abundance of daylight for plants and visitors.
“Overall, the project had two main goals. The first was to create a safe environment for humans (guests and staff), and non-human (animal and plant) populations inside and outside of the building. The second was to improve the overall efficiency of the envelope and functionality of the Rainforest habitat. Given the fact that the glass pyramid is a dominant envelope of the space, glazing choice played a crucial role in achieving the goals.”
Photo credit: Federal Hill Photography, LLC
Rule #1: Don’t Kill Birds
Civic sites like the National Aquarium are leaders in wildlife conservation and education, and that includes a commitment to protecting bird populations. The National Aquarium uses bird deterrent glass treatments for its properties, so of course the renovation of their landmark pyramid needed bird friendly glass as well.
We often talk about bird safe patterns when discussing bird friendly solutions, but full-surface treatments like the Walker Textures® Opaque finish used in this bird friendly glass pyramid can be even more effective. That’s because they make the entire surface of the glass visible to birds. While a full-surface treatment might not always be the answer for windows and other vision applications, a skylight like this one is a perfect case for full-surface etch. It’s important to note that, as with bird friendly patterns, the etch should be applied to the outermost surface of the glass (surface one). This way, the etch won’t be masked by reflections on the glass.
Best Practices for Bird Friendly Glass
If you have questions about how to design bird friendly buildings, our Bird Safe Glass resource page can help. You’ll find an overview of what can make glass safer for birds, case studies of successful bird safe projects, whitepapers from bird collision expert Dr. Daniel Klem, Jr., and answers to frequently asked questions on the topic. It’s a great place to start your bird friendly design process.
Photo credit: Federal Hill Photography, LLC
“A year has now passed, and I am SUPER happy with the glass panels provided for that project; it was an excellent choice for this application.”
We reached out to the National Aquarium a year after the project’s completion to see how the bird friendly glass pyramid was performing. Ken Howell, the Curator of Australia and Rainforest exhibits, told us, “I was a strong advocate for the surface one acid-etching that we eventually all came to agree upon. A year has now passed, and I am SUPER happy with the glass panels provided for that project; it was an excellent choice for this application. I have paid close attention to any possible bird strikes occurring on this glass and that number appears to be zero, which is not unexpected as the acid-etched glass is clearly visible to flying birds.”
Photo credit: Federal Hill Photography, LLC
Designing for daylighting
Full-surface etched glass wasn’t the only possible choice for this project, though. During the initial product selection process, Design Collective’s Director of Sustainability, Seonhee Kim, considered both AviProtek® E patterned bird friendly glass and Walker Textures® full-surface etched glass. Both approaches are proven bird-safe glass options. Both can be combined with Solarban® low-e coatings to improve energy efficiency. Both deliver up to 90% visible light transmittance, well over the project’s requirements. However, a full-surface etch has one advantage over patterned glass: it diffuses daylight.
Skylights like the National Aquarium’s glass pyramid can bring enormous amounts of direct sunlight into a space, which risks burning the leaves of plants and creating uncomfortable glare for visitors. Ultra-clear glass can present an additional challenge, simply because of the amount of light that passes through the glass. Fortunately, solving this problem can be as simple as using full-surface etched or “frosted” glass. The matte finish doesn’t reduce the amount of light that enters a building, but it scatters and distributes light throughout the space. This eliminates direct sunbeams and “hot spots”, making the environment much more comfortable for the plants, animals and humans inside.
How has this played out at the National Aquarium? Ken Howell told us, “the plants and animals living under the glass in the rainforest exhibit have responded very favorably to the glass provided.”
Expert advice for better daylighting in architecture
Daylighting can make or break an architectural design, so it’s important to know how to manage it. If you’re interested in designing beautifully lit buildings, you’ll want to read what these experts have to say.
- Seven golden rules for great daylighting in architecture
Our interview with daylighting expert Lisa Heschong about best practices for daylighting and views in the built environment.
Read the article - Let the sunshine in! How Acid-Etched Glass Improves Daylighting and Saves Birds’ Lives at the National Aviary Wetlands Habitat
How the greenhouse experts at Montgomery-Smith transformed the National Aviary Wetlands Habitat into a brilliantly daylit oasis.
Read the article - Full Surface Acid-Etched Starphire® Glass: The Designer’s Choice
Understand exactly where, why, and how to use low-iron glass with a full-surface acid etched finish, with tips from Nathan McKenna of Vitro.
Read the article
Photo credit: Federal Hill Photography, LLC
A Bright Future for an Icon
The renovation of the National Aquarium’s iconic glass pyramid not only restored its visual appeal but also brought the structure up to modern environmental and wildlife conservation standards. Following the goals of the National Aquarium and the team at Design Collective, Walker and Vitro were able to provide high-performance glass that combines energy efficiency, bird safety, and optimal daylighting. A year after the renovation, the success of this innovative glass solution is clear. With zero bird strikes reported and the rainforest exhibit flourishing under the new glass, the project stands as a testament to how thoughtful design can meet diverse needs.
Visually, the renovation has strengthened the Aquarium’s identity as a landmark Baltimore feature. Architect Seonhee Kim explains, “The Aquarium’s pyramid has been a part of Baltimore’s skyline since its opening in 1981. Its full surface finish provides a monolithic view (with a diffused glow during night) of the pyramid that accentuates its iconic shape.” The bird friendly glass pyramid once again shines as a symbol of Baltimore, reflecting the city’s commitment to sustainability and innovation.
About the National Aquarium
The nonprofit National Aquarium opened on August 8, 1981—the jewel of Baltimore City’s Inner Harbor redevelopment. With a mission to connect people with nature and to inspire compassion and care for our ocean planet, the Aquarium is consistently ranked as one of the nation’s top three aquariums. It is also Maryland’s largest paid tourist attraction, featuring thousands of fishes, birds, amphibians, reptiles and mammals in award-winning habitats.
