In North America, up to one billion birds die each year from glass collisions. Thankfully, bird-safe glass technologies offer a solution. However, as a new product category, the industry lacks standardized guidelines for testing and quality.
Thorough evaluation of bird-safe solutions is essential. While Vitro collaborates with wildlife experts for bird deterrence strategies, North American's largest glass manufacturer has used its expertise to create a rigorous testing protocol and best practices for effective use for its latest product: BirdSmart® Bird Safe Glass.
Birds See an Impassable Medium
Unlike humans, who rely on binocular vision for depth perception, birds depend on wider spatial vision to scan for food and landing spots. This limits their depth perception, making it hard to recognize glass as a barrier. Glass also reflects the sky and trees, creating illusions of real destinations, causing birds to fly toward them. This mix of poor depth perception, UV absorption and reflective surfaces often leads to bird collisions.
Growing Advocacy and Legislation
Growing awareness of bird collisions has led 25+ cities, states and provinces across the U.S. and Canada to enact bird-safe glass legislation. Federally, the proposed U.S. Bird Safe Buildings Act could mandate bird-friendly practices in federal buildings. Additionally, sustainable building rating programs, like the U.S. Green Building Council's LEED® v5, offer credits for bird-friendly designs under their Biodiverse Habitat category. These codes, green building programs and voluntary standards are increasing demand for architects to specify bird-safe glass.
Making Glass Visible to Birds
Bird-friendly glass uses visual markers to prevent bird collisions, with experts recommending placement on the exterior (first surface) for maximum visibility. A key North American standard is the “2" x 4" rule,” which states birds avoid gaps smaller than 2 inches high and 4 inches wide. Patterns following this rule significantly reduce collisions, though some experts recommend a stricter “2" x 2" rule” for added protection.
Bird Safe Solutions
BirdSmart® glass by Vitro uses laser-etched markers on the first surface. This non-caustic, chemical-free process differs from acid etching, which needs special facilities. Laser etching can be done anywhere. At Vitro, glass is laser-etched in the same facility where it's produced and coated, streamlining bird-safe glass manufacturing. When paired with low-e glass, laser etching doesn't affect solar heat gain or visible light transmittance (VLT). Rigorous testing confirms it also maintains the glass's strength, durability and easy cleaning.
AviProtek® bird-safe low-e glass by Walker Glass, in partnership with Vitro, combines acid-etched visual markers on the first surface with a Solarban® low-e coating on the second surface. This design boosts energy performance compared to ceramic frit bird-safe glass, which places the low-e coating on the third surface, reducing solar efficiency. Like laser-etched glass, acid-etched glass maintains solar heat gain and visible light transmission (VLT) properties.
While many birds can see UV rays, not all species do, making UV-coated laminated glass potentially less effective than etched glass, particularly at certain times of day.
Bird-Friendly Glass Testing Best Practices
Drawing on its expertise in current and emerging bird-safe glass ASTM standards, Vitro’s team of experts identified what it anticipates will become the industry-required tests for bird-safe performance. BirdSmart® glass was then thoroughly tested in five key areas: gloss, abrasion resistance, strength, stain resistance and weathering.
Flight Forward
Due to building codes, green building initiatives and voluntary bird-safe standards, more building owners are asking architects to include bird-safe glass in their designs. With more design options and increasing legislative support, increased bird-safe glazings show a growing understanding of the need to balance human development with wildlife protection.
The vetting and testing process of BirdSmart® glass serves as a valuable resource to the industry for evaluating bird safe glass performance. Read more here.
