The distribution of green walls and green roofs throughout Australia: Do policy instruments influence the frequency of projects?

Green roofs and green walls are gaining popularity as a means of mitigating a range of environmental impacts associated with urbanisation. Although this technology has been widely implemented in some parts of the world, uptake within Australia has been slow. This might be attributed to a range of factors, including a lack of awareness; a scarcity of urban green infrastructure policies; a lack of examples to give urban designers confidence in the technology; and perhaps also a limited number of professionals capable of installing green infrastructure systems. This paper researches the distribution of green wall and green roof projects in urban Australia, and the possible influence of local government policies and guidelines that have been designed to promote the increase of green infrastructure in Australia's cities. Differences were observed among project distributions and frequency, both within and between cities. In addition, councils that offered policy instruments and guidance tended to have more green wall and green roof projects than those which have no such policies in place. Compared to successful examples seen internationally, further policy implementation in Australia could increase the frequency of green infrastructure projects, indicating that governmental influence may play a substantial role in encouraging green infrastructure installation.