10 reasons that make green walls and roof gardens a good choice
by Nikola Tosic, 11 April 2017
Very often green walls and roof gardens are thought to be too expensive, like other ecological compensatory systems, but in reality, they can represent a profitable long-term investment while improving health and well-being.
Here are the main public, private and design-specific benefits provided by green walls and roof gardens.
- Noise reduction. The vegetated surface provided by strategic urban greenery such as green walls and roofs will block high-frequency sounds, and when constructed with a substrate or growing medium support can also block low-frequency noises.
- Reduction of the Urban “Heat Island” Effect. Green walls and roof gardens are an excellent heat reduction method: they absorb heat instead of attracting it, thus providing a natural insulation to the building and reducing energy costs. Green walls can reduce the temperature fluctuations at a wall’s surface from a range of 10-60ºC (50-140ºF) to one of 5-30ºC (41-86ºF).
- Improved air quality. Green walls and roof gardens mitigate air pollution levels through photosynthesis, trapping particulate matter, and capturing gasses.
- Savings. The ability of green walls to provide thermal insulation for buildings means less demand on power, and as a result, fewer polluting by-products are released into the air.
- Reduction of stormwater runoff. Roof gardens have a natural capability to reduce and slow stormwater runoff in urban environments. The velocity of stormwater runoff is a major source of flooding and pollution worldwide. A typical city block generates more than five times runoff than a woodland area. That is why green roofs absorb and filter water, avoiding also sewer overflows.
- Well-being. Buildings that feature and promote access to vegetation have been documented as having a greater positive human health impact than those without.
- Increased Biodiversity. Green walls and roof gardens can help mitigate the loss of biodiversity due to the effects of urbanization, help to sustain a variety of plants, pollinators, and invertebrates, and provide habitat and nesting places for various bird species.
- Urban agriculture. Green walls and roof gardens offer the opportunity for urban agriculture and the growing of small fruits, vegetables, and herbs.
- Aesthetic improvements. Green walls can reclaim disregarded space by providing aesthetic stimulation where it would not otherwise be found. They can also serve to create privacy and a sense of enclosure while limiting the negative psychological effects associated with property demarcation.
- Roof life expansion. Roof gardens protect the roof’s waterproofing membrane from external influences, which may lead to serious damages, and prevents accelerated aging due to UV degradation.