Focus topics

  • landscaping/habitat/biodiversity
  • dark skies

  • Bird-Friendly Design
  • Site Acoustics

Sustainable design protects and benefits natural ecosystems and habitats in the presence of human development. Describe the larger or regional ecosystem (climate, soils, plant and animal systems) in which the project is sited. In what ways does the design respond to the ecology of this place? How does the design help users become more aware of or connected with place and regional ecosystems? How does the design minimize negative impacts on birds and other animals (e.g., design to prevent bird collisions, dark-sky compliant lighting)? How does the project contribute to biodiversity and the preservation or restoration of habitats and ecosystem services?

Measure 3: Design for Ecology is unique among AIA COTE® Top Ten measures in that it focuses solely on nature. Although the strategies presented, such as keeping the night sky dark and minimizing undesirable noises, will improve the environment for humans, this measure asks design teams to think beyond the anthropocentric world of traditional architecture and to design specifically for the rest of biodiversity.

The number one strategy is to create landscaping with native plantings; this is a high-impact strategy for saving water, decreasing maintenance costs, and providing a habitat for local animals and insects. Compared to turf grass (the ecologically dead default solution that requires constant water and chemicals to stay green), native landscapes will literally buzz with life. Turf grass does have legitimate applications, such as for sports fields or play areas, but it should not be used as a decorative element.

The remaining strategies—dark sky, bird safety, and site acoustics—downplay the presence of the human world and make every site, whether a rural farmhouse or a downtown office building, a little more wild.

Landscaping/habitat/biodiversity

  1. Native plants have evolved to thrive in their local environments without irrigation or soil treatment. Cover as much of the non-building area as possible with a broad diversity of native plantings. This will also help create a comfortable microclimate.
  2. Before beginning to design, take some time to understand the local ecology and ecological services that are available on-site and throughout the bioregion. Developing the site in a way that protects or restores these ecological services links the land with ecological history.
  3. Preserve all on-site mature trees. Work with a landscape architect or arborist to assess existing tree health and appropriate building standoff distances. Establish and carry out a protection plan during construction.
  4. Use landscape elements to preserve or create habitat for local flora and fauna. Simple urban examples include birdhouses, bat boxes, and native plantings that support pollinators. Larger and more rural sites can create and preserve habitats for a wider range of species.
  5. Use landscaping as part of a natural pest control strategy. Plant species that repel mosquitoes and other pest insects. Maintain appropriate clearances between landscaping and the building to protect less durable building materials.
  6. Every bit of habitat counts. Even if the only possible intervention is a few native flowers in a planter box, those plants contribute to an ecosystem that can now support, for example, additional butterflies.

Dark skies

  1. Maintaining dark natural environments is a major consideration for exterior lighting design. Reference the outdoor maximum illuminance guidelines from the Dark Sky Society’s “Guidelines for Good Exterior Lighting Plans.”
  2. All exterior luminaries should be full cutoff and aimed toward the surface that needs to be illuminated. Every effort should be made to keep the luminary out of everyone’s line of sight.
  3. Site lighting should be scheduled to turn on at sunset and turn off by the time the occupants have left the property or retired indoors.
  4. Site lighting that remains on all night should be avoided. If nighttime site security is required, a combination of night-vision cameras and motion-activated lights can be used to keep the site both dark and safe.
  5. After following all the best practices above, consider computer simulation to verify that required night lighting remains out of the line of sight of windows. Tools such as AGi32 or ElumTools can be used to further verify.  

Bird-friendly design

  1. Roughly 100 million birds die every year in North America by flying into windows. Without bird-safety design, every building in the country will kill one to 10 birds every year. Strategies that prevent windows from looking like their surrounding environment will protect birds and the ecosystems that depend on them.
  2. Birds tend to fly into expanses of reflective glass. A dense exterior-shading system and low-reflectivity glass will make windows obvious to birds.
  3. Bird safety is yet another benefit of limited glazing area. Keeping the window wall ratio below 40 percent will improve energy performance, daylighting, and thermal comfort, and will reduce bird deaths.
  4. Minimize glass in the tree canopy or near water features to avoid causing reflected foliage and water to look like they continue into the building (the oasis effect).
  5. Bird-safe glazing has a pattern that birds can see but humans cannot. It is more expensive than standard glazing but allows for unobstructed expanses of glass that birds are less likely to fly into.
  6. Include bird-friendly design solutions in all documentation and presentation graphics to keep all stakeholders informed of this goal and to ensure that nothing fall through the cracks.

Site Acoustics

  1. Some site elements, such as compressors or chillers, create unwanted site noise and vibration. It is important to work with engineers to specify quieter equipment and to place these elements away from spaces used by people or animals. The design team has less control over other acoustical sources, such as highways or flightpaths. In these situations, shape the building or other site elements in a way that shields the occupants and their neighbors from site noise.
  2. The most effective way to control environmental noise is by physically blocking the source with a solid barrier. The barrier should be placed as close to either the source or the receiver as possible. The closer to the halfway point the barrier is, the less effective it will be. Shielding noise sources with plantings is significantly less effective.
  3. Send unwanted noise to the sky by angling sound barriers upwards. This is more effective than a flat surface that will reflect it back toward the source. An example is the curved sound barriers used at airports.
  4. The amount of sound that can travel through the air is determined by the air’s density. Air becomes denser as it gets drier or colder, creating more environmental acoustical challenges in dry or cold climates.
  5. Some examples of sound-masking strategies include water features, wind features, kinetic art, beehives, and pollinator gardens.

Additional information

This publication is designed to provide accurate and authoritative information in regard to the subject matter covered.It is published and distributed with the understanding that the publisher is not engaged in rendering professional services.  If professional advice or other expert assistance is required, the services of a competent professional person should be sought.

Image credits

Center for Sustainable Landscapes_Denmarsh Photography, Inc_Lower_Level_Terrace

Denmarsh Photography Inc.

2007JG30.410

Jeff Goldberg/Esto

JoseyPavilion_CaseyDunn_EntryWalk

Casey Dunn

MPES_Courtyard Girls

Prakash Patel