What is a Living Wall?
Living walls are panels of plants, grown vertically – using hydroponics or substrate-based growing media – on structures that are either freestanding or attached to walls.
Because the walls have living plants in them, the larger projects usually feature built-in irrigation systems. But for most DIY green wall systems, just watering them by hand will be enough.
History of Living Walls
What makes living walls so fascinating to us is just how recently they have been popularised.
Green walls were were first developed by Stanley Hart White, a professor of landscape architecture at the University of Illinois.
In 1938, he created a patent for his ‘vegetation-bearing architectonic structure and system,’ but the invention didn’t really take off. So it stayed as a singular entity in his back garden.
Patrick Blanc – a French botanist who specialised in tropical forest undergrowth – is generally the man credited with popularising green walls.
He worked with an architect (Adrien Fainsilber) and engineer (Peter Rice) to implement the first large indoor green wall or Mur Vegetal in 1986 at the Cité des Sciences et de l’Industrie in Paris.
What does a Green Wall do?
What a green wall does is dependent (partially at least) on:
- Where it’s situated: inside or outside
- The types of plants used: edibles for food, perennials for colour, thicker moss or faster growing ivy for thermal performance
- Aspect and climate: More sunlight and a suitable climate will increase the rate of growth and wall’s performance
There are a host of other benefits associated with green walls including:
- Sound insulation
- Mental wellbeing
And some research has also shown that living walls may help purify grey water – gently used water from bathroom sinks, showers, tubs, and washing machines.
External Living Walls
Used on a building’s exterior, green walls help insulate a building and improve the heating and cooling cycle(s).
This means you will lose less heat in the winter and retain less heat in the summer.
By reducing the overall building temperature through solar radiation and preventing warm air from leaving the building, your heating and air conditioning expenditure will reduce.
Internal Living Walls
Plants naturally remove carbon dioxide and produce oxygen-rich air (via photosynthesis), whilst also filtering the air around them by absorbing and cleaning pollutants.
But the benefits of green walls go beyond air quality or insulation. Really one of our favourite proponents of a living wall is the creativity associated with them. You can build something living and completely unique in your own home.
And as a city dweller myself, space is hard to come by. So making use of your walls in more ways than one is something to be immensely proud of.
What are Living Walls made from?
Well of course there are different types of living walls. The two main types of living wall build are:
- Sheet media systems
- Mat media systems
For sheet media systems, the living wall is made of an egg crate-patterned plastic sheet that is typically used for larger projects.
Because of the added depth and texture of the sheet media systems, they are able to hold significantly more water than the mat media system, and can last much longer because the plastic isn’t biodegradable.
Mat media systems are usually composed of thin-coir fibre or felt mats of multiple layers which are best for interior use and with smaller plants.
Because the mats aren’t particularly sturdy, they cannot support larger plants with thicker, longer roots that could potentially rip the mats and compromise their integrity.
Although these mat systems are easy to install, the thinness of the mat makes them unable to hold much water, and therefore they aren’t very water-efficient. However, for smaller installations with smaller plants, they can be a great solution.
How do Living Walls work?
Green walls are constructed much the same way actual walls are. You build a base to work from – a skeletal structure – and hang the plants and flowers from or within modular trays, troughs, trellises or in planters.
But they all work in largely the same way. Of course it depends on your green walls purpose in life – to feed, to improve air quality or thermal performance.
But as the flora and fauna reach maturity the wall’s ‘performance’ improves.
- Your home’s ability to retain heat in winter and cool in the summer could reduce your bills.
- You can become more self-sufficient food-wise
- Noise levels are reduced
But so much of this relies on you properly caring for your wall. Trimming and weeding when appropriate, watering or ensuring the irrigation system works properly.
Green Walls vs Green Façades
Firstly let’s define what a green façade is.
- Green walls are living panels of plants grown vertically in a growth medium supported by the wall itself
- Green façades are plants that hang and climb on the wall, but are rooted in the ground
Green facades typically support climbing plants that climb up the face of the wall. A classic interpretation of a green facade would include ivy. While green walls can accommodate a multitude of plant species.
And green facades are always outside. Green walls can feature as internal air purifiers or artistic installations.
Types of Green Façades
And there are two types of green facades:
- Indirect green facades incorporate a structure that will support it for plants
- Direct green facades which are attached to the wall
How long does a Living Wall last?
Typically somewhere between 4 – 6 years. But of course this relies on a number of variables:
- Is your wall indoor or outdoor
- Types of plant
- Climate
- Maintenance requirements
You’ll need to replant most plants in that timeframe, but the structure and setup of your green wall should last.
