Do You Know Your Green Wall Lingo?
While my primary focus is blogging about interior living walls, I think it’s time to identify all the different green wall technologies that exist inside and out. Green wall industry experts actually have specific lingo for differentiating the categories and sub-categories of green walls.
So here is a little vocabulary lesson to help you communicate clearly with clients and colleagues.
The term ‘green wall’ is the best term when speaking broadly about vertical vegetation systems. It might also be called:
- Vertical Garden
- Living Green Wall
- Vegetated Wall
- Living Wall
- Vertical Greenery
But be careful. According to green wall industry experts, certain terms may actually be more appropriate for specific types of green walls. For example, a living wall is a type of green wall, but a ‘green wall’ isn’t necessarily a living wall. Confused yet? Let me explain.
As the green wall trend caught on worldwide, great strides in research and relentless product development have taken vertical greening to a whole new level. Particularly in the last 30 years, innovation in product design has spawned green walls for several different applications. Unsurprisingly, then, several terms began to surface to describe the green walls.
There are three main categories of green walls: green façades, living walls, and green retaining walls. While all of these green wall types seek to vegetate the vertical plane, they go about doing so differently.
Green façades usually feature plants climbing from ground level soil or from planter containers. Green façades can be sub-categorized as directly-attached or indirectly-attached. A directly-attached green façade simply refers to climbing vegetation (e.g. Boston Ivy, English Ivy, Virginia Creeper) growing directly on the wall structure. This is as simple as a green wall gets, and the effect can be gorgeous. On the other hand, the generally aggressive plants used might hinder maintenance and possibly damage the building envelope. Addressing those concerns is the indirectly-attached green façade, which utilizes a climbing structure to facilitate plant growth. The climbing structure might be a trellis system or a strong cable, wire, or rope. A couple great examples are Greenscreen and Jakob Rope. I would think that green façades are limited to exterior applications, but indoor greening might be feasible under the right conditions.
Living walls are what I’ve been specifically blogging about. Living walls use modules or layers affixed to a wall or structure to hold plants on a vertical plane and are appropriate for indoor or outdoor applications. Living walls can be sub-categorized into modular living walls, vegetated mat walls, and biofiltration walls. Modular living walls (or modular green walls) use specialized trays, panels, or modules filled with an engineered growing medium. Examples include GSky and Modulogreen. Vegetated mat walls feature layers of synthetic fabric and a hydroponic system to support the plants. Sometimes called Mur Végétal, this type of system was pioneered by Patric Blanc. Biofiltration walls are designed to improve air quality and regulate indoor air. It’s not news that plants passively improve air quality indoors. But biofiltration walls can actively filter air and support the HVAC system. A great example is the Nedlaw system.
Green Retaining Wall
The green retaining wall (aka living retaining wall, living landscape wall), sometimes considered a sub-category of living wall, has a very unique application. Green retaining walls serve the dual purpose of stabilizing a slope, thus creating more developable space, while accommodating vegetation as a green feature. Green retaining walls are typically modular, and contain pockets designed to hold volumes of growth medium and support vegetation. Depending on the system, green retaining walls can facilitate groundcovers, perennials, grasses, and even small trees and shrubs. Filtrexx International is one provider of green retaining walls and slope reinforcement systems.
In an industry this new, the nomenclature is still up for debate. But unless your business wants to install and maintain interior and exterior green walls (not a bad business model!), it’s still good to know the difference between a green façade and a living wall when talking with a project lead!