Have you ever looked outside your window, saw the garden on top of our Podium Stack and thought, “I wonder what that’s for?” Have you just looked at these roof top treasures and simply thought they were there simply for decoration? Well these roof top ecosystems serve many different purposes to their buildings as well as the community and Earth.
Ecoroofs or Greenroofs are rooftop gardens built to serve a variety of purposes. They consist of a root barrier, a waterproof membrane, drainage, soil system and finally, plants.
These layers combine to help the building and environment with a variety of purposes. The plants help with removing pollution and carbon dioxide from the air, as well as helping control storm water runoff by utilizing the water for growth, rather than allow the water to simply runoff into drains. Some buildings, including Cyan/PDX, have additional holding tanks that store the water that hits the ecoroofs for usage in drier months.
The plants on the ecoroofs also help with climate and noise insulation. In the warmed months, the plants absorb the heat from the sun and use it for energy opposed to allowing the building absorb this heat. Additionally, much like drapes in a sound chamber, these plants also help absorb noises to help keep buildings throughout the city a little quieter.
Because of these benefits, you can see why the City of Portland would want to encourage the creation of these throughout the city. The city would like to increase the amount of ecoroofs from the 11.5 acres we have now, to 49 in the next three years.
By using these previous vacant roof top spaces, we will be increase the plant life throughout the city providing us with all of those benefits that the ecoroofs bring.
