Glass Collisions

Existing Bird-Friendly Legislation & Ordinances

Vassar Bridge Science Building, N.Y. ©Christine Sheppard
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When writing legislation, ABC recommends starting with our Model Ordinance and Guide to Writing Legislation. In addition to focusing on the resources that we have created to help you, it can be useful to survey existing legislation and guidelines. We are listing these below.

ABC's legislative goal is to ensure that bird-friendly building design standards are applied to as many buildings — i.e., as much glass — as possible. This is why our Guide to Writing Legislation is comprehensive. None of the existing legislation and ordinances evaluated below goes as far as ABC's Model Ordinance for two reasons: 1) politics often requires working with other viewpoints and making compromises, and 2) later ordinances have been modeled on early ordinances that do not go as far as some of the ordinances being enacted today. Below, you will see language, common features, and the types of exemptions and restrictions that have been included in existing bird-friendly building legislation. Hopefully, your legislation will one day be added to this growing list.

The legislation and ordinances below are split into categories based on ABC's assessment of their overall effectiveness. Each entry has a very brief summary and a link to the full language from the official site of the pertinent governing body. We have included only the relevant portions so that you do not have to search for them. (Many of the code documents are hundreds of pages long.)

If you decide to delve into the legislation available below, we recommend reviewing the full text in the "Recommended" and "Recommended with Reservations" categories and spending less time with the "Not Recommended" section. While having bird-friendly guidelines on the books is better than not having any, the "Not Recommended" regulations do not apply to enough buildings and should therefore not be the basis for new guidelines.

In the event that you borrow language from any of the existing ordinances listed below, ABC highly recommends using the definition of bird-friendly glass (and all other definitions) found in our Model Ordinance because it provides the largest number of bird-friendly materials.

In general, we believe that the most direct route to drafting a good set of guidelines is to start with the full text and definitions of the Model Ordinance and modify as necessary.


How to Keep Birds from Hitting Your Windows

Are birds colliding with your home or building? Use our guide to find solutions and protect birds!


Mountain View, CA, U.S.A. (2017)

  • Mandatory. Applies only to the North Bayshore area. All new buildings, additions, and alterations should use bird-friendly materials for 90% of the façades up to 60 ft. Includes requirements for lighting and for treating hazardous features. See pages 125-126 in the pdf for the text.

New York City, NY, U.S.A. (2019)

  • Mandatory. Local Law 15 requires that all new buildings in the City of New York, from houses to skyscrapers, use a minimum of 90% bird-friendly materials in the first 75 ft. above grade. Covers auxiliary structures and includes requirements for hazardous features.

Toronto, Ontario, Canada (2010)

  • Mandatory. Guidelines that apply to: a) all industrial, commercial, and institutional development, b) residential development ≥4 stories, and c) low-rise residential development near natural areas. 85% or more of all exterior glazing, and all hazardous features, must be bird friendly up to 12 m above grade.

Why Birds Hit Glass

Birds, unlike humans, are unable to understand or learn the concept of ‘glass' as an invisible barrier that can also be a mirror. Birds take what they see literally – and glass can appear to be habitat they can fly into, whether the habitat is reflected, or seen through a pane of glass.

Photo of hummingbird


Canadian Standards Association (CSA), Canada (2019)

  • Model. Model guidelines for all buildings that communities can adopt as mandatory. Use >90% bird-friendly glazing to 16 m above grade and 4 m adjacent to a green roof — or to the height of the mature tree canopy — whichever is greater. The CSA specifies but does not define “high contrast” for markers. Based on available data, the minimum marker sizes specified are too small and should be increased. The CSA also requires surface-one treatments, but at present this limits available materials and should be expanded to include effective surface-two treatments.

Emeryville, CA, U.S.A. (2020)

  • Mandatory. Applies to all new construction and window replacements. For areas of contiguous glass of ≥12 ft.2, ≥90% of the glazing on any façade or glass structure, and all glass near plants or water features, must be bird friendly. Includes lighting requirements. Removing the 12 ft.2 contiguous glass trigger would make this more effective.

LEED Credit SSpc 55 Bird Collision Deterrence, version 4 (2015)

  • Private Guidelines. An optional credit in the US Green Building Council's LEED program that covers any building submitted, it can be adopted as an ordinance to cover any/all buildings. It requires that buildings have total building Bird Collision Threat Ratings of ≤15. This system uses a weighted average that estimates collision risk for all materials on the building envelope, where lower sections — Façade Zone 1, which is ≤36 ft. above grade and ≤12 ft. above green roofs — have more weight than the materials above that. Includes requirements for lighting, post-construction monitoring, and addressing hazardous features.

Madison, WI, U.S.A. (2020)

  • Mandatory. Applies to buildings with >10,000 ft.2 of total above-ground floor space: For façades with >50% glass in the first 60 ft. above grade, 85% of the glazing must be bird friendly, along with all glazed corners; façades with <50% glass in the first 60 ft. above grade must treat >85% of glass areas >50 ft.2 along with all glazed corners. Includes hazard features. Ideally this would be adopted without the 50 ft.2 exemption and would include more buildings by reducing the building square-footage threshold.

Minnesota (State), U.S.A. (2013)

  • Mandatory. Applies to state-owned new buildings and major renovations. Whole-building Threat Factors, which are analogous to the weighted average calculation for LEED Pilot Credit #55, are used to define requirements (non-critical sites = 45; critical sites = 15). Includes hazardous features and lighting. See especially pages 6-7 and 57-66.

Portland, OR, U.S.A. (2012)

  • Mandatory. Applies to the Central City Plan District, new buildings (all façades with ≥30% glazing in the first 60 ft. from grade) and major renovations (all façades where ≥75% of the façade is altered and where the façade has ≥30% glazing in the first 60 ft. from grade). In these cases, ≥90% of windows and glazing must be bird friendly, using materials in the Portland Bird Safe Windows List. Includes hazardous features; excludes low-rise residential.

Washington, D.C., U.S.A. (2017)

  • Voluntary. Listed here because it would rate as “Recommended with Reservations” if mandatory. Part of the 2017 District of Columbia Green Construction Code, to receive optional bird collision deterrence credit, buildings must be built to LEED Credit SSpc55 Bird Collision Deterrence.

Take Action for Birds

ABC is working hard to make federal buildings bird friendly. Join us today and ask Congress to pass the Bird-Safe Buildings Act!


Communities that have adopted the following legislation are to be commended for having taken action to address the bird collision crisis. However, the following are listed as Not Recommended because they contain such a large number of exemptions that ABC feels they do not apply to enough glass/buildings and thus are not effective enough.

Alameda, CA, U.S.A. (2018)

  • Mandatory. Applies to new construction and window replacements for unbroken glazed segments >12 ft.2 only on buildings >35 ft. tall that also have ≥1 façade with ≥50% glass. For those buildings, >90% of the glass must be bird friendly. The definition of “bird-friendly” needs revision. Includes large auxiliary structures. Several additional exemptions. Includes lighting.

Calgary, Alberta, Canada (2011)

  • Voluntary. General information on bird-friendly building design that does not have specific design rules.

Cook County (unincorporated), IL, U.S.A. (2008)

  • Mandatory. Applies to new construction and major renovations and states that these should follow bird-friendly building principles (provides references). No specific guidelines. Includes retrofits for existing buildings “where practicable.” Exempts the city of Chicago.

Highland Park, IL, U.S.A. (2020)

  • Mandatory. Specifies that the City shall consider bird-friendly design “to the greatest extent practicable” in the construction of new City buildings. No mention of non-municipal buildings and no specific guidelines. Points to bird-friendly building documents for review that are also provided by the building department during project registration.

Howard County, MD, U.S.A. (2020)

  • Mandatory. Applies to: 1) publicly funded new buildings ≥10,000 ft.2 gross floor area, and 2) non-publicly funded new buildings in specified occupancy categories that are also: a) ≥50,000 ft.2 gross floor area or b) ≥10,000 ft.2 gross floor area in downtown Columbia. Other exemptions included. Specified buildings must be built to LEED Credit SSpc55 Bird Collision Deterrence or equivalent standard.

Markham, Ontario, Canada (2014)

  • Voluntary. Significant information on bird-friendly building design with suggested design rules and strategies not written in building code language.

Minneapolis, MN, U.S.A. (2016)

  • Mandatory. Applies only to new skyways. >85% of all glazing should be bird friendly.

Oakland, CA, U.S.A. (2013)

  • Mandatory. Applies only to buildings near a substantial body of water or green space of >1 acre or to those that have a green roof.  >90% of all glass must be bird friendly within 60 ft. above grade. Includes lighting.

Palo Alto, CA, U.S.A. (2015)

  • Mandatory. Not an ordinance but instead a standard condition applied during permitting for new commercial buildings. Requires adherence to the City and County of San Francisco (see below).

Richmond, CA, U.S.A. (2016)

  • Mandatory. Essentially exempts residential buildings. Also exempts almost all non-residential buildings because requirements apply only to non-residential buildings that: have >10,000 ft.2 floor area and are >2 stories and are within or adjacent to green spaces/water of >2 acres — and for those buildings, the only façade that needs to be bird friendly (>80% bird-friendly glass) is the one facing the open space. Includes lighting.

San Francisco (City & County), CA, U.S.A. (2011)

  • Mandatory. Applies to new buildings, additions, and significant renovations that are within an urban bird refuge (>2 acres of greenspace or water) or that are within 300 ft. of a refuge and have a clear line of sight to it. >90% of the glass in the first 60 ft. must be bird friendly. Exempts many residential buildings. Includes hazardous building features and lighting. San Francisco broke ground with this ordinance in 2011, but an update is overdue.

Santa Cruz, CA, U.S.A. (2019)

  • Mandatory. Only applies to projects that require design review and are adjacent to or within 300 ft. of a natural area or waterway. Requires that >90% of all glazing must be bird friendly in the first 40 ft. above grade. Includes lighting.

San Jose, CA, U.S.A. (2019)

  • Mandatory. San Jose Downtown Design Guidelines and Standards. Applies only to buildings with >50% glazing that are also within 300 ft. of a riparian corridor. Does not specify percentage treatment requirements. Includes hazard features and lighting.

Vancouver, British Columbia, Canada (2015)

  • Voluntary. A loose set of bird-friendly building and landscaping recommendations.

Visit our photo gallery to see how a variety of materials and techniques can be used to make buildings safe for birds and great for people.

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Bird Collisions on ABC's Blog

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