City of Chicago, IL, USA

Ordinance O2020-136 (Mandatory)

Ordinance O2020-136 prioritizes two strategies from the Chicago Sustainable Development Policy, which are required for new construction:

1) 9.1 Bird Protection (Basic).

2) 9.2 Bird Protection (Enhanced).


The Department of Planning adopted the following best practices from the Chicago Bird Collision Monitors with the goal to reduce both bird collisions and fatalities:

  • Minimum: “95% of all facade areas up to thirty-six (36) feet above grade and above green roof, roof garden or landscaped deck shall have a threat factor of thirty (30) or less.” Priority given to high-collision areas that include lobbies, atriums, or any areas where greenery is close to glass

  • Desired: “95% of all facade areas up to thirty-six (36) feet above grade and above green roof, roof garden or landscaped deck shall have a threat factor of thirty (30) or less; and requires that at least 60% of all facade areas above the first thirty-six (36) feet have a threat factor that is no more than thirty (30).”

  • Optimal: Treat windows so that all areas have a threat factor that is less than thirty (30). Offers guidelines for types of window treatments and appropriate spacing pattern to be used by building owners, contractors, etc.

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