The Basics and the Promise of Green Walls for Cities
Can living walls improve the quality of urban life?
Eco Brooklyn founder and entrepreneur Gennaro Brooks-Church first started building living walls (also known as green walls or vertical gardens) because he thought they looked cool. “Planting a living wall is like painting,” he says. “I love the creative process of designing patterns and picking plants and textures that work in this environment, making it a living work of art.” In the summer of 2018, after he completed his most ambitious project to date--the entire facade of his brownstone townhouse in Brooklyn, he was caught off guard by a much deeper insight.
“There is something here that makes a lot of sense in the city environment,” Brooks-Church continues. “People don’t even realize it in but in New York City, we are so starved for nature.” They stop in front of his building to take photos, or to just stand quietly. And when he walks out of the house he will often get comments like “This is so amazing.” The most common expression he receives from onlookers is just to thank him for having built it.
What is a green wall?
A green wall refers to a wall or a portion of one that is covered with vegetation. They can utilize a hydroponic system or a growing medium. In the case of Brooks-Church’s townhome in Brooklyn, the growing medium is coconut fiber with a binder. It is watered with drip irrigation. Green walls can be built for both indoor or outdoor settings, and vary in size from a small panel to an entire facade. Green walls are different than green facades, the latter with plants growing from soil only at the base of the wall and climbing up it.
The Benefits of Green Walls
Aside from aesthetics, there are other benefits to installing green walls. In the winter, plants help insulate a building, keeping the property warm and decreasing the cost of heat. In the summer, greenery reverse-insulates, making a home cooler and reducing the cost of air conditioning.
They help counter the urban heat island effect. Other positive effects include the creation of natural habitat, privacy screening, acoustic buffering and graffiti protection.
Brooks-Church has found, however, that when it comes to making the decision to install a living wall, the spiritual aspect wins the day versus the practical benefits.
“It’s not like ‘Oh wow, the insulation value of my house is going to increase, so I’m going to buy one’,” he says matter-of-factly. “It’s not like, ‘Wow, it is going to filter my air better.’ It is more like, ‘That’s so beautiful, I want one.’”
Will Green Walls Damage the Supporting Structure?
Brooks-Church says that a green wall is different than a green facade that has climbing plants such as ivy that rest directly on a brick surface, and which can cause damage. During construction of a green wall, on the other hand, the wall is waterproofed to protect the structure from moisture and root penetration.
How Much Maintenance is Required for Green Walls?
“Maintenance is key, especially in the first six months,” Brooks-Church says. Frequent initial adjustments to irrigation or lighting may be necessary. By the end of that initial period, however, he notes that walls usually will have “found their rhythm” and he can scale back the frequency of maintenance visits to monthly, bi-monthly, or even three months.
Maintenance elements of a green wall can include water delivery and fertilization, replacement plants as well as potentially weeding and pest management.
Cost of Green Wall Construction
Prices can vary, depending upon the job, but according to one source, the cost for a living wall system, including vegetation, is in the range of $195-$265 per square foot. Another website suggests a range between $280 and $350 for a typical 20 x 20-inch summer panel.
Various Green Wall Projects
Green walls can be used in many applications, ranging from interior to exterior, and from retail and office environments to residential applications such as the Brooks-Church townhouse facade in Brooklyn. Green walls can enhance industrial buildings, parking lots, hotels, schools, hospitals and highway structures. The Via Verde project in Mexico City, for example, involves turning 1,000 highway pillars into vertical gardens.
“Living walls are the future,” Brooks-Church concludes. “If you Google ‘Utopian City’ you see nothing but images full of nature. We are biophilic creatures, so our ideal habitat is full of natural elements. And in NYC where land is limited and costly, where else can you build but up? Living walls are perfect for NYC.”