Site and Water Guidelines

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SS.14 Bird-Safe Building

Sustainable design can create environments that are attractive to birds which benefits both occupants and wildlife. Any built environment, but especially those attractive to birds, can pose a risk for bird-building collisions, which kill hundreds of millions of birds per year. The intent of this guideline is to limit the risk of built environments to birds, with special attention to the highest risk conditions. Some other B3 Guidelines guidelines also affect bird-safe building such as S.1 Avoidance of Critical Sites, S.4 Sustainable Vegetation Design, and S.5 Light Pollution Reduction recommended criteria S.5B and S.5C

TF: Threat Factor, a property of a building material related to likelihood of bird collision, found in the Threat Factor Table (See Appendix S-14a)

Required Performance Criteria
For New Construction and Major Renovations with new or replacement glazing scope, all required criteria apply. For Major Renovations without new or replacement glazing scope, only S.14E (Follow “Lights Out” light management program) is required

  1. Traps (Highest Risk Surfaces) shall be less than TF 25
    Any material in the following conditions must have a Threat Factor less than or equal to TF 25
    • Glass/Plexiglas (transparent) railings (all surfaces exposed to exterior)
    • Glass/Plexiglas-sided walkways (eg. sky ways, covered walks with glass on two sides)
    • Any glazed surface that offers a see-through situation that is 20ft or less across, such as a small atrium, or glass corners
  2. High Risk Surfaces are limited to 15% of surface area with TF 75 or more
    No more than 15% of the area of a “High Risk Surface’ shall have a threat factor greater than or equal to TF 75. A High Risk Surface is defined as:
    • A surface within fifty feet or less of attractants such as trees, shrubs, prairie, grassland or open water (including green roofs with this type of vegetation)
    • A surface in a see through situation greater than 20 feet across (such as atriums, gathering spaces/lobbies, etc.)
  3. Whole Building Threat Factor (WBTF) shall be less than or equal to WBTF 45; or WBTF 15 for Critical Sites

    Use the B3 Guidelines Bird-safe Design Calculator (Appendix S-14a) to determine WBTF. The calculator will also document and help to meet requirements for S.14A , S.14B, and S.14D. Use Guideline S.1 criteria to determine if the project is on a “critical site” to determine the appropriate WBTF threshold.

  4. Non-Enclosure Threat Factor (NETF) shall be less than or equal to NETF 45

    Use the B3 Guidelines Bird-safe Design Calculator to determine NETF for non-enclosure surfaces.

  5. Follow “Lights Out” light management program
    Follow “Lights Out” light management program which addresses operation of lights at night for specified times and dates of bird migrations. In addition to the B3 Guidelines requirement, note that this is also required by law for state owned and managed buildings. (
    • Dates: Between March 15 and May 31 and between August 15 and October 31 each year
    • Times: Between midnight and dawn
    • Lighting: Turn off building lighting including but not limited to: architectural lighting at top of building; up-lighting; interior lighting, especially on upper floors; and lobby or atrium lighting. Exception: where lights are documented to be needed between midnight and dawn for normal use of the building, they may be operated.
  6. First Year Building Monitoring
    For one year after construction/occupancy, walk the perimeter of the building(s) and all accessible set-backs and roof areas at least two times per week. Document survey activity and findings as required in Appendix S-14b Bird Safe Monitoring Worksheets.

Recommended Guidelines:

  1. Meet Whole Building Threat Factor (WBTF) of less than or equal to 15
    Use the B3 Guidelines Bird-safe Design Calculator (Appendix S-14a) to determine WBTF
  2. Enhanced Bird Safe Building Monitoring
    In addition to S.14 F (First Year Building Monitoring) above:
    • Continue First Year Monitoring Format for one or more additional years (shifting to a January-December Calendar year basis in ongoing operations phases of the tracking tool)
    • AND/OR Conduct more surveys per week for first or more years
    • AND/OR Work with an organization such as Audubon Minnesota to collect and catalog birds found.
  3. Bird Safe Building Narrative
    Complete a Bird-Safe Case Study Narrative Report to document and share your bird-safe efforts. Use Appendix S-14c Bird Safe Building Narrative Template or include a write up with similar content.
  4. Bird Safe Lighting Design
    Comply with recommended lighting guidelines S.5B and S.5C and Document Bird Safe Features of lighting including for S.5C; identify how control zones relate to Lights Out program

Compliance Tools and Resources

Related B3 Guidelines Documents


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