Sedums and other plants adorning walls as living tapestries have captivated our attention. The general consensus is that this is a positive trend. But how do you know if this type of project is the right addition for your space or building?

Consider the benefits. Exterior living walls have many of the same benefits of green roofs. The vegetation absorbs light and heat that would otherwise directly and negatively affect both the exterior and interior of the building. The living wall shelters the exterior of the structure from the elements thereby extending life of the construction. The insulation it provides successfully reduces the energy needed to cool and heat the interior of the building.

Even beyond insulation, the vegetation goes a step further and decreases the ambient air temperature naturally through transpiration. The temperature seldom rises 4-5 degrees Celsius above the ambient air temperature.

There is not much research as to the exact amounts that living walls help with stormwater runoff, but as gravity pulls the stormwater from the roof, the wall is bound to have an impact, albeit less than a green roof.

Interior living walls not only reduce the temperature, but naturally purify the air of harmful chemicals found in paint, photocopiers, cleaning agents, and other indoor pollutants. Office buildings are often insulated and the air continuously recycled with the same pollutants. Living walls offer a natural air filtration and have been built with a fan behind the wall to help circulate the purified air.

Indoor walls with a basin at the base of the wall offer the opportunity to recycle water over and over again. Water is distributed through a drip system at the top of the wall and it eventually filters down into the water receptacle below the basin. A pump is used to bring that same water back to be dripped from the top again.

The aesthetic benefits of a green wall will be difficult to go unnoticed. Exterior living walls are a novelty in the tri-state area that makes a public statement about the owners’ values and ideals. Psychologically a message can be conveyed that this organization is quite literally “down to earth.”

Interior walls are usually less grand, and while they make a similar statement, the employees or tenants who are directly affected by the close proximity to the living wall can take the message personally. The feeling that their well being and enjoyment is a consideration can improve morale and increase retention.

Here’s how it works
Modules with layers of organic or inorganic growing material, water retention fabric, and vegetation are installed and attached to a metal frame that is anchored to the wall. A gap of 6” ensures the benefits of the living wall will still be realized by the structure without the water or moisture damage that may occur when plants are in direct contact with the building.

Image courtesy of vegetal i.D.

This kind of system can be sustained for ten to fifteen years without needing replacement. The modules allow for easy and healthy replacement of wall sections because the plants’ roots are not attached the wall itself, not intertwined with surrounding modules. This protects the surrounding plants and modules if a section needs replacing.

Some living walls also have a layer of stainless steel screen above the growing material. This is to help stabilize the plants, much like a trellis for a vine and help to support the growth of the plant outward instead of being weighed down.

Drip irrigation systems from the top of the wall filter water slowly to the vegetation and gravity pulls the water to the whole vertical garden. Some irrigation systems have even effectively recycled gray water to hydrate the living wall.
Contact us to determine whether a roof garden is right for you.