We’ve written in the past about green roofs, but there is a whole other side to these projects that we neglected to mention. When we say ‘side’ we mean it literally, because green walls are a new trend that we’ve seen recently emerge that has us very excited. Operating much in the same way a green roof does, a green wall’s main goal is to promote energy efficiency amidst larger metropolitan areas, but there are several different types of green walls that help achieve this goal. From underutilized space on the side of office and apartment buildings, to greenery growing along and through a fence, green walls go a long way to making an ecological difference.
Green facades, as greenroofs.org points out, “…are systems in which vines and climbing plants or cascading ground covers grow into supporting structures that are purposely designed for their location.” Green facades can stand on their own or be affixed to existing walls. This means that they’re perfect to use as fences to border a walking trail.
Living walls are exactly what they sound like. They’re ‘…composed of pre-vegetated panels, modules, planted blankets or bags that are affixed to a structural wall or free-standing frame. [They] can be made of plastic, expanded polystyrene, synthetic fabric, clay, and concrete and support a greater diversity and density of plant species.” Simply put, living walls are walls that are given life with a variety of plant life, from ferns to flowers, and even edible plants – which in some ways means you’re getting life from the plant as well. Some major cities have already started to adopt living walls. One of the most prolific examples is the living wall at the Yonge & Eglinton Centre in Toronto.
Retaining Living Walls
Almost like a hybrid between green facades and living walls, retaining living walls are “engineered living structures that are designed to stabilize a slope while supporting vegetation contained in their structure. They provide the structural strength to resist the lateral forces exerted by angles greater than the natural angle of repose of soil and protects against erosion.” Because of the difficulty of installing a sloped unit, retaining living walls are often modular. The goal is to be completely covered by vegetation, so the initial structure is no longer visible. These types of green walls are the perfect compliment to a gradual slope like that near a body of water.
Benefits of a Green Wall
As we mentioned before there are a number of benefits to the installation of a green wall, not the least of which are the aesthetics. Green walls add a splash of life that’s even more visible than on display with a green roof. Green roofs are lovely to look at, but unless you’re standing on the roof, or are somehow above it, the benefits are mostly logistical. A green wall can be enjoyed at nearly every angle, turning a potentially dreary building into a beautiful living thing.
Additionally, green walls work to reduce the urban heat island effect because of the vegetations natural cooling process. They also improve exterior air quality. Because of the lack of greenery in urban environments, as well as the raised level of carbon emissions, air pollution is a very real concern. Green walls can help mitigate pollution levels.
On a private level, buildings with green walls will experience some of the same benefits as those with green roofs. Installing a green wall improves a building’s energy efficiency. With their natural Sun absorption and cooling properties, less heat enters a building which equals lower cooling costs. This in turn helps protect the building’s structure over time. Long term temperature fluctuation can be damaging to a building. A green wall’s natural temperature regulatory effects on a building can help resist these effects. The indoor air quality improves as well. According to greenroofs.org, “Air that has been circulated through a building with a strategically placed green wall (such as near an intake valve) will be cleaner than that on an uncovered building.”
These are just some of the benefits that come with installing a green wall, but there are many others. It’s heartening to see buildings like the Ryerson Campus in Toronto engage with ecologically friendly projects like their green roof program, but densely packed metropolitan cities need to think bigger, and greener. Green walls offer huge benefits, not only to big cities like Toronto, but as the trend picks up, potentially the entire country.