2 | p a g e
typically in reducing bird collisions, but not exclusively, evaluated per a binary
choice flight-tunnel protocol involving live birds. A TF of 1 represents least
threatening and a TF of 100 represents most threatening. A TF of 50 indicates no
effect in reducing bird collisions, and materials with a TF greater than 50 have
attributes that may contribute to collisions. For more information on determining the
Threat Factor, see the definition of Bird Friendly Material below.
2. Assembly
A discrete combination of materials, which can include glazing, louvers, or screens
(i.e. materials in front of glazing), and other combination of materials or use of
evaluated strategies.
B. Clarification of Terms Defined in the NYC Building Code
1. Bird Hazard Installation
The New York City Building Code defines Bird Hazard Installation (BHI) in Section
1402.1, as follows:
“Bird Hazard Installation: Monolithic glazing installations that provide a clear line of
sight on the exterior of buildings, including, but not limited to glass awnings, glass
handrails and guards, glass wind break panels or glass acoustic barriers.”
Chapter 14 of the New York City Building Code establishes the minimum requirements
for exterior walls; wall coverings; wall openings; windows and doors; architectural trim;
balconies; projections; and other appendages. As stated above, Section BC 1402.1
defines Bird Hazard Installations as monolithic glazing installations, and Section BC
1403.8.2 requires BHIs to be constructed of Bird Friendly Materials regardless of
height. For the purposes of Section BC 1403.8, monolithic glazing shall mean glass
and glazing, in accordance with Chapter 24 of the New York City Building Code,
including but not limited to single pane or laminated glass, light transmitting ceramic,
light-transmitting plastic panels for exterior use in both vertical and sloped applications
in buildings and structures, as well as light transmitting plastics, in accordance with
Chapter 26 of the New York City Building Code. Glazing extensions of façades,
whether up, down or to the side that do not enclose indoor space, and glass fins
greater than 10 inches from the face of the exterior wall envelope, highlighted yellow
in Figure 1 below, are considered Bird Hazard Installations. The elements highlighted
in blue are not considered Bird Hazard Installations.
Highly reflective metal façade panels and highly reflective solar passive roofs
(silver/white) do not constitute BHIs as defined above. However, even if a façade
element or material does not constitute a BHI, exterior wall envelopes still must comply
with the balance of the requirements for providing bird friendly materials found in
Section BC 1403.8. Bird Hazard Installations constitute elements that protrude more
than 10 inches from the face of the exterior wall envelope of a building and are see
through (i.e. provide clear line of sight). Exterior Wall Envelope is defined in Section
BC 202 as follows: