The New Normal: Common types of green infrastructure

Green Roofs

  1. Extensive – usually Sedum, lightweight, low maintenance and water needs, cheapest to install and maintain
  2. Semi-intensive – usually a mix of low growing grasses and sedum, medium weight, maintenance and water needs, more expensive to install and maintain
  3. Intensive – supports a variety of plant life (trees, shrubs, lawns) which have higher maintenance and water needs; being the heaviest they are the most expensive to install and maintain
      • Green roofs insulate the building which keep them cool in the summer resulting in lower utility costs
      • Plantings absorb the sun’s rays instead of reflecting them back into the atmosphere like a traditional roof.
      • This reduces the heat island effect experienced in the city.
      • Contrary to popular belief, all types of green roofs actually help protect the membrane and will double its lifespan by protecting it from UV rays and regulating temperatures. Any membrane problems can be traced back to flaws in the original installation.
      • Retards fire due to the water content in soil and plants.

Rain Gardens
With climate change, comes more erratic and severe weather patterns including heavy rainfall. A rain garden is a strategically located depression in the landscape designed to catch, hold and clean storm water directed from impervious areas such as parking lots and roadways. By mimicking the natural absorption and pollutant removal properties of a forest or meadow, they can absorb runoff 30-40% more efficiently than a lawn.

    • Rain gardens capture, hold and clean particulates from the water keeping items like cigarette butts out of the ocean
    • They reduce the need for irrigation in dryer times due to their water holding ability
    • Because they drain within 12-48 hours, they do not create a breeding ground for mosquitos, contrary to popular belief

Living Wall or Green Façade?
A living wall consists of plant material covering a wall that is either growing in soil or hydroponically in water. A green façade is plant material growing up or along a wall or trellis system from the ground.

    • Regulate temperature inside the buildings they rest on, reducing utility costs
    • Increase the lifespan of the building envelope by protecting it from external influences (e.g. UV rays)
    • Absorbs sound and reduces noise