Urban development often harms wildlife. Birds hit glass, nocturnal animals get disoriented by city lights and habitats disappear. However, various wildlife-friendly retrofits prove that existing buildings don’t have to be bad for nature. Here are cost-effective strategies and retrofit building examples that showcase innovative design.
How Do Buildings Affect the Environment?
The impacts of existing developments on wildlife are often overlooked. While retrofitting and sustainable construction can reduce carbon emissions, they can inadvertently destroy wildlife habitats and harm animals. Research found that over one billion birds die annually in the U.S. from building collisions, many of which occur at low- and mid-rise buildings, not just skyscrapers.
Homes and buildings one to three stories tall are responsible for 44% of bird deaths. Larger, low-rise establishments four to 11 stories high caused 339 million fatalities.
Core Principles of Wildlife-Friendly Retrofit Buildings
Many people have witnessed birds hit a building, recover from it and fly away. It’s normal to assume that they survive, but the staggering death toll reveals the urgent need for bird-friendly building design. Here are the main principles for wildlife-friendly retrofit establishments.
1. Visibility and Transparency
Birds do not instinctively recognize glass as a barrier. Many mistake reflections of the sky and landscapes for open space, leading to fatal collisions. Consequently, clear glass may appear as an open pathway or an extension of the space they’re in or attempting to reach. They may see vegetation on the other side and perceive it as an accessible route.
2. Light Pollution Reduction
Lighting can attract migrating birds from as far as five kilometers away, reducing their energy levels and visibility of the starry night sky. This is particularly common on nights with foggy weather or low-cloud ceilings, when avian species tend to migrate at lower altitudes.
Many nocturnal predators rely on darkness for hunting, while their prey relies on darkness for cover. Artificial light can expose prey to predators or make it harder for predators to ambush effectively. It can also disrupt the foraging behavior of nocturnal species.
3. Enhanced Biodiversity
Urbanization inherently leads to the loss of natural habitats, isolating wildlife populations and making them vulnerable to local extinction. Integrating native landscaping and habitat features can transform buildings into essential components of a more diverse ecosystem.
Cost-Effective Strategies for Existing Buildings
Retrofitting existing buildings for wildlife compatibility doesn’t require significant expenses. Many strategies are budget-efficient and may yield long-term ecological benefits.
1. Glass Treatments and Window Modifications
Subtle patterns, geometric shapes, lines, or dots on the glass surface can eliminate reflections or transparency. Highly budget-conscious projects may rely on temporary, practical solutions like nontoxic tempera paint or simple tape strips. Installing external insect screens also creates a physical barrier and distracts from reflections.
For an impressive retrofitting buildings case study, consider the renovation of The Sister Cities Café. Bird Safe Philly found it highly prone to collisions due to fall and spring migration, so it installed bird-protective window film with patterned dots in October 2023. No collisions were documented during the spring of 2024.
2. Lighting Retrofits
Lighting upgrades provide ecological and financial benefits. They’re something people could do in their own homes, too. For example, retrofitting a bungalow could involve adding insulation to attics and walls or replacing old windows with double-glazed ones. Motion sensor lights can help minimize light pollution and unnecessary illumination.
While not a physical retrofit, establishing programs that help limit interior lighting can be helpful. One example is the “Lights Out” initiative in New York. Buildings were invited to turn off lights and close window blinds to reduce excessive lighting and help birds navigate the skies safely.
3. Facade Upgrades
Install simple trellises, mesh systems and wires on building facades. While this requires a high upfront cost, these solutions offer immediate, long-lasting benefits, like reduced reflectivity and bird strikes. Using sustainable and durable materials like aluminum, which are 100% recyclable, provides high security and is low-maintenance, and combining these facades with low-reflective glass promotes better bird protection.
Some retrofit buildings include the Aqua Tower and the New York Times building. Chicago’s Aqua Tower’s facade and irregularity were partly designed to allow birds to see it more clearly and minimize collisions. Meanwhile, the New York Times building used fritted glass clad with rods to blur the lines between indoors and outdoors.
4. Landscaping and Site Modifications
Creating micro-habitats is an impactful, wildlife-friendly retrofit. A green roof has a 224% return on investment and can provide vegetation, food, and habitats for local wildlife. Incorporating rock and log piles in less-trafficked areas may provide shelter, nesting sites, and foraging areas for insects and small mammals.
Brighton, UK’s Bee Bricks initiative aims to protect the solitary bee population from the effects of urbanization. The Green&Blue company developed bricks to provide nests for solitary bees, which make excellent additions to training walls and garden beds.
Promoting Wildlife-Friendly Cities
These cost-effective strategies can make urban areas more wildlife-friendly. Smart use of glass treatments, facades and careful landscaping can ensure a harmonious coexistence between humans and animals.
