Walker Textures™ AviProtek - Bird Friendly Glass

The bird friendly glass product line offered by Walker Textures™ AviProtek, makes it one of the most effective bird safe glazing solutions on the market today.

Bird collision with building glass facades occurs across North America and is the major cause of bird mortality, claiming the lives of millions of birds each year. The magnitude of the problem is such that an important trend has emerged to make buildings more bird friendly.

The need for buildings to be less threatening to Wildlife is also part of emerging green strategies. The US Green Building Council’s Leadership in Energy and Environmental Design (LEED) recognized this by adding Credit 55: Bird Collision Deterrence, to their Pilot Credit Library in October 2011. The key component of this credit is the quantification of the threat level to birds on different glazing materials.

The 2x4 Rule

Glass surface treatments that reduce significantly the risk of bird collision have been researched by many experts such as Dr. Martin Rössler, Dr. Daniel Klem and Dr. Christine Sheppard. Their conclusions have consistently shown that most birds will not fly into surfaces that have two inches or less of untreated horizontal space or four inches or less of untreated vertical space. This criteria is commonly referred to as the “2x4” rule.

  • Horizontal

    2x4 rule horizontal
  • Vertical

    2x4 rule vertical


Exterior Surface

In a meeting held in April 2013 on bird-friendly building design, Dr. Klem stated that “For clear and especially reflective panes, bird strike prevention methods must be applied to the outside facing surface of windows to be effective.” A second example, discussed in the Bird Friendly Design publication from ABC, states that ceramic or “fritted” patterns on the internal surface “may not be visible if the amount of light reflected from the frit is insufficient to overcome reflections on the glass’ outside surface”. This is particularly true from an angled view.

Clearly, patterns designed in accordance with the 2x4 rule that are acid etched on the exterior surface of the glass most effectively deter bird collision. This is because they reduce reflections to a much greater extent, compared to patterns applied on the internal surface.

When privacy is required, glass entirely etched on either surface also offers excellent protection against bird collision.


Benefits of Walker Textures™ AviProtek

  • Full surface etching on either side of the glass
  • Patterns etched on the outside surface of the glass, offering an optimal combination of viewing areas and attractive bird safe designs meeting the 2x4 rule
  • Excellent “threat factors”, ranging from 5 to 29.8 on position 1
  • Effective both from a direct or angled view
  • No significant impact on the level of visible light transmission
  • The resistance properties of the closed pore surface of acid-etched glass are equivalent to unetched glass and offer the only suitable solution for treatment on the outside surface 
  • Can be combined with energy efficient glass, in a double glazed unit
  • 10 year limited warranty
  • Pattern 211

    bird safe glass pattern 211
  • Pattern 213

    bird friendly glass pattern 213
  • Pattern 214

    bird safe pattern 214
  • Full Surface

    bird friendly glass

Walker Textures™ AviProtek Offering

  • Colors: Clear and ultra-clear, others available on demand
  • Thicknesses: Standard 6mm, others available on demand
  • Dimensions:
    • Patterns: Standard 96’’ x 130’’
    • Full Surface: Standard 96’’ x 130’’ up to 100’’ x 144’’
  • Threat Factors:
    •     ​Patterns:  29.8 on position 1 (70.2% of times birds will avoid collision)
    •     ​​​Full Surface:
      • 5 on position 1 (95% of times birds will avoid collision)
      • 25 on position 2 (75% of times birds will avoid collision)

Note: According to ABC’s standard, a bird-friendly building should have at least 90% of exposed façade material from ground level to 40 feet that has been demonstrated in controlled experiments to deter 70% or more of bird collisions.


AviProtek patterns are also available with a low-E coating on surface 2. Click here for more information:

Bird Safe Low-E Coated Acid-Etched Glass


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For more information on bird conservation visit any of the following web sites:


Useful Information


Is Walker Textures™ AviProtek the right solution?

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