The Future Of Green Walls
Like so much green technology, living walls are extremely expensive to install. However, this innovation has an advantage over other eco-developments – its beauty. Unlike solar panels or wind turbines, green walls are undeniably aesthetically pleasing. The motivation for their installation is almost always to enhance the appearance of a building, with the environmental benefits often a secondary concern.
Green Facades and Living Walls
Green walls are an advance and application of the same ideas and technologies needed to place a green surface on a building’s roof. The spectacular effect of a vertical garden running up the side of a building can be achieved in two ways. The first type of green wall, known as a green facade, utilizes climbing plants, rooted in the ground, supported by specially constructed frames.
The second category, known as a living wall, consists of plants living in vertical panels of a growing and developing medium, sustained using a hydroponic system. It is this second type that has the most potential, both aesthetically and environmentally.
Environmental Benefits of Living Walls
Although the aesthetics and uniqueness of living walls are undoubtedly the driving force behind their current popularity, there are also many environmental benefits to green walls:
- Reduction of thermal loading to buildings - lowers heating and cooling costs and lowers carbon emissions
- Reduction of heat island effect - less reflected heat
- Storm water attenuation - panels can absorb over 30kgs per m2 of rainwater
- Air purification - plants are efficient filters of pollution, especially when used indoors
- Noise reduction - quieter buildings and streets
- Increased urban biomass - the ecological habitat is increased even with non-native plant species
Problems With Green Walls – The Failure of Paradise Park's Living Wall
Growing plants on a vertical plane on the side of a building is obviously unnatural. The technology of living walls is still being developed and solutions to the problems relating to installing feeding and maintaining plants in a vertical garden are still being addressed.
A couple of high profile failures at pioneering walls have lead to concerns over the long-term viability of green walls. The most famous of these was the death of the living wall at Paradise Park in London, UK. The wall at the Islington Children's Centre, installed in 2006, was the first large-scale green wall in the UK, and received a great deal of publicity. However, after a short three years the wall was dead. A combination of factors, including the choice of plants, the water pumps, human error, and the growing medium panel design, has been blamed for the death.
Since Paradise Park, and other early failures, green walls have been greatly refined and can now be found adorning office blocks, houses and museums around the world.
Living walls are currently an aesthetic add-on but in time, as the quality of the technology supporting vertical gardens is refined, they may have a serious role to play in the sustainable future of our urban built environment.