Author: Ella Chen
Editors: Kevy Chen and Rachel Chen
Artist: Chiara Chen
The trend of urban densification, which has accumulated throughout the years, raises various environmental concerns such as climate change and increased carbon emissions. To address these concerns, people have adopted the practice of building green roofs and living walls, structures covered with vegetation and greenery that improve biodiversity and air quality. This practice also provides a solution to the urban heat island effect, wherein urban areas have higher temperatures than surrounding areas.
Green roofs, or vegetated roofs, consist of a waterproofing membrane with several layers: a root barrier, a drainage layer, and a growing medium (typically soil). The most important part of green roofs is the vegetation planted on top of the waterproofing membrane. It helps cool and shade the roof, reducing temperatures in the surrounding air and mitigating the urban heat island effect. Implementing green roofs can reduce city-wide temperatures by 5 degrees Fahrenheit, promoting a more comfortable and high-quality environment. They also slow stormwater runoff, filter out pollutants from rainfall, act as building insulators, decrease greenhouse gas (GHG) emissions, and lower energy costs. Although green roofs may be more expensive to construct than conventional roofs, they are significantly more beneficial and have a longer lifespan, ultimately making them a worthwhile investment.
Similar to green walls, living walls are walls or vertical surfaces covered with vegetation. The vegetation can be grown in two ways: through pockets of soil attached to the wall, or through hydroponic systems where nutrients are received through water. Unlike green roofs, the structure of living walls allows plants to grow vertically, making them visually appealing. While green roofs and living walls share benefits such as lower temperatures, reduced energy costs, and improved biodiversity, only living walls can be used indoors as well as outdoors. This versatility means they can be implemented anywhere from small office buildings to large skyscrapers. Indoor usage of living walls can improve air quality as plants filter out carbon monoxide and other pollutants from the air and exchange them for safe-to-breathe oxygen. Additionally, living walls have noise reduction capabilities; the foliage acts as an added barrier, deflecting sound waves and creating a more pleasant ambient environment.
The use of green roofs and living walls has demonstrated promising solutions to the ongoing environmental crisis, and installing more green roofs and living walls will likely lead to significant positive impacts on the environment. Not only do green roofs and living walls offer a range of environmental benefits, but they also contribute to a healthier lifestyle and improved well-being for everyone living in urban settings. Despite concerns about the costs of implementing these structures, the long-term benefits ultimately outweigh the initial costs. The application of these innovative practices is essential to effectively addressing the challenges posed by the environment.
Citations:
filipeboni. “The Green Revolution: How Green Roofs and Living Walls Are Transforming
Urban Spaces.” UGREEN, 26 Mar. 2023, ugreen.io/the-green-revolution-how-green-
GSA. “Green Roofs.” Www.gsa.gov, 4 June 2021, www.gsa.gov/governmentwide-
Manso, Maria, et al. “Green Roof and Green Wall Benefits and Costs: A Review of the
Quantitative Evidence.” Renewable and Sustainable Energy Reviews, vol. 135, no. 1364-
0321, Jan. 2021, p. 110111, https://doi.org/10.1016/j.rser.2020.110111.
US EPA. “Using Green Roofs to Reduce Heat Islands.” US EPA, US EPA, 17 June 2014,
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