Introduction
It’s quite possible you’re already familiar with the idea of a ‘living wall’ – maybe you’ve seen old properties enveloped with vines, you might have seen the art project currently underway in Rio de Janeiro (see the picture above), or perhaps you’ve just been unlucky enough to witness a mildew outbreak in your house! These are all examples of living walls, but don’t touch on the ecologically minded living walls, a more modern concept which is becoming increasingly popular within the circles of architecture and design.
Eco Living Walls – A Definition
Definition from www.knowledgerush.com:
“A living wall is a vertical garden. The plants grow in compartments on a porous vertical wall. The water drips down, and may feed moss and vines, other plants, some insects and bacteria. The water is captured at the bottom of the wall in a pool or pond to be re-circulated to the top.” (http://knowledgerush.com/kr/encyclopedia/Living_wall/)
Definition from www.wikipedia.com:
“A green wall is a wall, either free-standing or part of a building, that is partially or completely covered with vegetation and, in some cases, soil or an inorganic growing medium. They are also referred to as living walls, biowalls, or vertical gardens.” (http://en.wikipedia.org/wiki/Living_wall)
Eco living walls – exterior applications
The use of living walls in a building’s facade is an increasingly popular practice amongst architects, with examples popping up around the world, from Spain to the US to South Korea. But, apart from the obvious, what makes these vertical gardens green?
One of the main environmental problems in cities arises from the huge surface areas of concrete, asphalt, and other similar materials created by densely packed buildings and extensive road networks. These materials absorb radiation from the sun (heat energy) very efficiently, so the very fabric of the city is heated, and this energy is subsequently re-radiated, heating the air further. As a result of these ‘urban heat islands’, cities are often 3-4 degrees hotter than surrounding rural areas. The main knock-on effect this has for the environment is the increased use of mechanical cooling systems.
Eco living walls can help to combat this urban heat island effect, as can green roofs, since plants and other greenery absorb far less heat than massive construction materials. The temperature of the building’s fabric is therefore lower, so as a result its contribution to the heat energy contained in the surrounding air is lower. Problem solved!
‘Living facades’ can also have a positive effect on a building’s internal environment. In winter months the air cavity between the living wall and the building’s structure acts as an extra layer of insulation, and the living wall itself acts as a barrier against winds. The latter is especially useful since, in winter, wind chill factor can account for up to a third of heating demands. In the summer, the living wall provides increased shading for the fabric of the building hence one will often see them used on South and West facing walls (in the Northern Hemisphere that is!).
Eco living walls – interior applications
As you can see from the image above, eco living walls aren’t just limited to exterior applications! There is a growing demand for living walls inside buildings, the effects of which can also be highly beneficial to the living environment. With the correct selection of plants, a living wall can actually remove or trap dust, toxins and other unhealthy contaminants from the air inside a building. This is a great, natural way to achieve excellent air quality, and a good method to help prevent ‘Sick Building Syndrome’ (yes, this does exist!) The filtering effect can be made more efficient if the air a building draws in can be passed directly over a living wall as it enters the building.
Most eco living walls built for interior applications consist of a vertical arrangement of plants or organisms supported by a simple irrigation system. These irrigation systems often feature a tank of water at the base of the wall, which has a cooling affect on the interior environment.
Depending on your choice of plants, your living wall can also become an ‘edible wall’ – sounds like something out of Willy Wonka’s factory! A lot of herbs, salad greens and other vegetable plants are suitable to use in living walls, so they can even help to cut your food bills!
And Finally…
Let’s not forget amongst all these green benefits, eco living walls are also beautiful. They are often received as works of art and provide excellent focal points both inside and outside buildings. So, they are good for the environment, good for your health, good for your food bills, and great to look at. Not bad for a few plants on a wall!
Bio
Written by Simon Thorpe, a 3rd year Architecture Undergraduate at Magdalene College, Cambridge. Simon spent 2 months in the summer of 2009 as an intern for Eco Vida, ecological architects and green building experts. Tel +34958126272, info@ecovida.co.uk, www.EcoVidaInternational.com. Contact Simon at simoncthorpe@hotmail.co.uk
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