Retrofit : Volume 6 Issue 1 2017
RETROFIT AUSTRALIA • VOLUME 6 NUMBER 1 | 2017• 47 Green Spaces | serve as community hubs, increasing social cohesion, a sense of community and public safety, especially in low- income and high-rise housing. Urban agriculture – Using green roofs as the site for an urban agriculture project can reduce a community’s urban footprint through the creation of a local organic food system and reduce living costs for families, especially at low socio-economic levels. Living walls Living walls are vertical vegetated systems for any structure. There are three different types: a green wall that relies on a structure to hold growing media; a vertical garden that relies on a felt hydroponic structure; and a green facade, which is a post-tensile network of mesh, wires or grids to support vines and creepers. Public benefits: Reduction of the urban heat island effect – Combined with green roofs, their potential use throughout a CBD on buildings to create ‘green canyons’ can provide profound benefits to air quality, visual beauty, wellbeing, a reduction in ozone (a major cause of asthma) and reduced ambient air temperatures. Improved exterior air quality – Living walls mitigate air pollution levels by lowering extreme summer temperatures through photosynthesis, trapping particulate matter and capturing gases. Private benefits: Improved energy efficiency – Living walls can reduce the temperature fluctuations at a wall’s surface from a range of 10–60 degrees Celsius to one of between five and 30 degrees Celsius, in turn limiting the movement of heat between building walls. They cause this reduction by: • trapping a layer of air within the plant mass • reducing ambient temperature via evapotranspiration and shading • creating a buffer against wind during winter months. Living walls can help lower the air temperature around intake valves so that HVAC units will require less energy to cool air before being circulated around a building. Improved indoor air quality – It has been estimated that problems associated with poor indoor air quality negatively affect workplace production by $60 billion per year in the United States (Reitze 1998). Design-specific benefits: Increased biodiversity – Living walls can help mitigate loss of biodiversity due to the effects of urbanisation; help sustain a variety of plants, pollinators and invertebrates; and provide a habitat and nesting places for various bird species. Improved health and wellbeing – Buildings that feature and promote access to vegetation have been documented as having a greater positive human health impact than those without. Other benefits include: • urban agriculture • on-site wastewater treatment. Green Roofs Australasia is a not-for-profit industry peak body promoting green infrastructure for incorporation into the urban fabric. Membership and sponsorship are relied upon to continue our advocacy for green cities – using plants, the real green. Go to www.greenroofsaustralasia.com.au or email: firstname.lastname@example.org.
Volume 5 Issue 1 2016