Living in Harmony

Above: Bird-friendly glass types, left to right: digitally printed, FlySafe laminate, UV strips, BirdSecure laminate, acid etch

The Bottom Line: Tools, questions and answers to help equip you and the homeowner.

With ever-expanding urbanization, the impact of human development on various birds has become a significant concern. Bird-friendly glass, designed to minimize bird collisions with buildings, has emerged as a viable long-term and cost-effective solution. According to the American Bird Conservancy, an estimated one billion bird deaths per year are attributed to building design, making the issue immediate and pressing.

This article explores a different angle: bird-friendly glazing for residential use. To date, bird-friendly mandates have focused on public, commercial and low-rise residential buildings. We aim to explore the requirements, benefits, drawbacks and technical ramifications of bird-friendly glazing in single-family homes and luxury residential spaces. 

Deciding on bird-friendly glazing 

The big question surrounding the use of bird-friendly glass for homes is whether the homeowner must use bird-friendly glazing, or if it’s a “nice-to-have” solution. Legislation throughout the U.S. and Canada is ever evolving, and focuses primarily on low-rise residential, commercial and public spaces. Though a step in the right direction to minimize bird strikes, no legislation yet exists for bird-friendly glazing in single-family homes. 

This leaves the decision to use bird-friendly glazing squarely in the hands of the homeowner. 

Interestingly, an estimated 36% of the one billion bird strikes occur at single-family dwellings. That’s 360 million bird deaths due to homes alone. With such a high percentage of strikes occurring in this segment, it wouldn’t be surprising to see bird-friendly mandates bridge into this area as well. 

For the time being, it’s important to remember that the bigger and more luxurious the window, the higher potential for bird strikes. If the home is designed with expansive glass, it may be a worthwhile endeavor to highlight the pros and cons of bird-friendly glazing to the homeowner, architect or general contractor. 

Pros of Bird-Friendly Glass

Migratory bird safety. The main benefit of bird-friendly glass is its ability to reduce bird collisions. Traditional windows are reflective and can easily confuse birds, leading to fatal collisions. Birds cannot differentiate between the reflection of a tree and the real thing. Thus, bird-friendly glass incorporates dots or patterns through digital ceramic frits, acid etching, UV banding or “dotted” laminates that “break” the reflection and provide birds with visual cues. 

Durability. The current lineup of bird-friendly glazing options is designed to last for the lifetime of the glass. Print, acid etching and UV technologies are proven long-term solutions and should be used in place of decals or other non-permanent products. 

Cons of Bird-Friendly Glass

Aesthetic concerns. Incorporating bird-friendly elements into residential windows may be regarded as visually unappealing by homeowners and architects. The reality is that bird-friendly glass and glazing will require some visual markers unless costs reduce, and/or sizes increase, for UV-based solutions, which are invisible to humans. This is where a narrative becomes important—is the homeowner willing to contend with bird strikes? 

Cost considerations. Bird-friendly glass may have a higher initial cost than traditional glass options; however, these costs vary widely depending on the type of bird-friendly glass the homeowner or architect selects. For example, UV glass costs considerably more than digitally printed bird frit, acid etch or laminated solutions. 

Technical considerations

Size. Sizing considerations should be considered. For example, ceramic frit allows a window to be sized at 130 inches by 300 inches—up to the largest size in North America—but choosing a UV option will limit the overall window size to 102 inches by 144 inches. 

Pattern alignment. If implementing a window-wall system or residential curtainwall, it’s important to work with glass fabricators to align the glass appropriately. Care should be taken to justify the pattern and limit visual clutter from misalignment (Figure 1).

Low-e coating integration. The benefit of all bird-friendly glass is that it can be used with low-emissivity coatings. In many cases (especially in jumbo glass), the low-e coated glass must be a laminated outboard configuration or be used on the inboard lite of a double or triple insulating glass unit if lower thermal and solar heat gain coefficient performance is acceptable. Refer to the Residential Bird-Friendly Glass table below for examples of possible configurations; hover over Low-e Integration Options to view the illustrations.

Many manufacturers and fabricators can implement first-surface bird frit and second-surface low-e coatings. Your mileage may vary depending on the sizes available. Some examples are included in the table. 

Bird-friendly glass is a fantastic solution for the homeowner looking to take an additional step toward bird safety. Though bird glazing comes with challenges and considerations, the outcome is proven: fewer bird strikes, a healthy environment and cleaner surroundings for the homeowner.

Understanding the deterrent type, costs, sizes and technical considerations will help you better inform all home design stakeholders, while also providing questions you may wish to ask your glass fabrication partner. 

Bird-friendly resources 

The National Glass Assoc. has technical resources about bird-friendly glass available in the Store and on glass.org.

• Bird-friendly Legislation (webinar)
• Saving Birds with Effective Glass Solutions (free one-pager to download)
• Bird-friendly glass resources ( NGA Store)