New Directions for Living Roofs and Walls

New Directions for Living Roofs and Walls

The evolving technology of green roofs has been leading to the use of greater diversity in their designs. After years of implementing green roof designs, the international industry has seen a steady move towards more diversity in both elements of construction and plant materials. What is most fascinating of the improvement in green roof design is the use of plants on these roofs which, along with other naturally decomposing materials, aid in greater biodiversity. No longer are sedums the only plants that are being used on green roofs. At the EcoBuild Conference in London 2010, exhibits featured new green roof designs showing a greater use of ornamental grasses and other flowering plants including some bulbs. The exhibitors even hinted at the use of materials that compose brown roofs. A brown roof is comprised of loose material as in crushed concrete or woody debris. This material can be combined with some self-seeding plants or left for nature to care for; however, the belief is that brown roofs will colonize spontaneously and will also provide habitat for several local species (i.e., bats, birds) as well as migrating species.

These new projects are so diverse they can help to support a large population of invertebrates including bees, wasps, and spiders.In addition, we see a growing interest in living walls. Living walls! What are they? They are walls of plants that can be free standing, attached to a building or built on a structure. Living walls come in many varieties. There are self-established walls, moss gardens/mat, climbers, and those derived through other technologies, such as hydroponics, modules, or cells. These walls provide many of the same benefits as a green roof would, in that they can help cool down an area, provide health benefits, and can aid in the reduction of heat and air-conditioning while creating greater habitat for birds and many invertebrates. Living walls can also assist with dust suppression, noise abatement, evaporative cooling, and shade provisions.The thermal benefits of vegetation along walls can maintain a temperature of 30° Celsius (C) when a road or non-vegetated wall reaches a temperature of around 46° C. Living walls are wonderful because they can be so diverse. As mentioned earlier, there are many types and we can grow a wide range of plants on them. Some, like self-established walls, are easy to maintain and relatively inexpensive. Take an ordinary rock wall and overtime, seeds will drop or land on it and take root. They can become quite thick with plants but they are slow to establish and may not do well in sunny, dry locations. They will, however, offer a great diversity of plants, if allowed. Climbers are limited to those plants that will climb exterior walls or wired structures, which limit the range of plants that can grow on them. With hydroponics, modules or cells exciting walls can be created that allow for plant diversity, unique designs, and creative arrangements. Although these systems are expensive, require irrigation systems and may require specialists to install and maintain, they can add a very attractive element in a design and can enhance indoor and outdoor spaces tremendously.

The wall provides visual interest, aids in scaling the size of the building to create a space for people to sit or stroll along while having a pleasant and positive experience.

Germany and Austria have been the leaders in green roofs for many decades now. In Linz, Austria, all new construction built after 1985 must have a green roof installed on it. The change has been remarkable. Green roofs and living walls are beneficial for our environment in reducing urban heat island conditions, reducing dust, cooling spaces, and habitat for several species in an urban. India too needs to include more green roofs and living walls in new construction and in existing construction by offering subsidies and other fiscal incentives to local and regional government agencies. We need to continue to raise the public’s awareness to get the support of policymakers.