High-rise glass buildings pose immense dangers to birds. In the United States alone, up to 2 billion birds are killed yearly due to collisions with glass, according to the

. To reduce those numbers, the glass industry has fabricated specialized architectural glass and has worked with regulators to produce guides and standards.

This includes the addition of “

” in ASHRAE 189.1 and the International Green Construction Code. The addendum was approved by ASHRAE and the American National Standards Institute on Jan. 30, 2026. It introduces a new bird-friendly design requirement for building facades to promote uniformity around glazing requirements. It is written as a jurisdictional option to fit a region’s particular environment.

“Research on bird-friendly glazing for collision prevention has guided the development of bird-friendly building design,” reads the addendum’s forward. “Creating visual markers on the glass at a specific spacing and geometry to interrupt reflections and transparency has been shown to significantly reduce bird collisions. This addendum specifies requirements for the location and characteristics of this type of glass.”

The addendum’s language applies to vertical windows, spandrel glass, skylights, corner glazing and glazed railings in areas up to 100 feet above grade in new buildings and major alterations. According to Section 5.3.7 of Addendum o, bird-friendly glass should be installed in a new vertical fenestration area that is being replaced during existing building renovations. Bird-friendly glass may be installed in locations:

Furthermore, the first or second surface of the bird-friendly glazing should have opaque, translucent or ultraviolet reflective visual markers not smaller than 1/8 inch, not more than 2 inches between linear continuous visual markers and a density pattern such that a circle with a diameter no more than 2.7 inches will fit between discrete point visual markers. The glazing should also have a bird-friendly configuration, including opaque, etched and ultraviolet reflective markers approved by the jurisdiction.

Several exemptions to the above section include places of religious worship and buildings on the National Register of Historic Places.