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

Accepted Manuscript Title: The distribution of green walls and green roofs throughout Australia: Do policy instruments influence the frequency of projects? Author: P.J. Irga J.T. Braun A.N.J. Douglas T. Pettit S. Fujiwara M.D. Burchett F.R. Torpy PII: DOI: Reference:

S1618-8667(16)30502-7 http://dx.doi.org/doi:10.1016/j.ufug.2017.03.026 UFUG 25886

To appear in: Received date: Revised date: Accepted date:

15-11-2016 17-1-2017 30-3-2017

Please cite this article as: Irga, P.J., Braun, J.T., Douglas, A.N.J., Pettit, T., Fujiwara, S., Burchett, M.D., Torpy, F.R.,The distribution of green walls and green roofs throughout Australia: Do policy instruments influence the frequency of projects?, Urban Forestry and Urban Greening (2017), http://dx.doi.org/10.1016/j.ufug.2017.03.026 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

The distribution of green walls and green roofs throughout Australia: Do policy instruments influence the frequency of projects? PJ Irga, JT Braun, ANJ Douglas, T Pettit, S Fujiwara, MD Burchett, FR Torpy

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Plants and Environmental Quality Research Group, Applied Ecology Team, School of Life Sciences, Faculty of Science, University of Technology Sydney, P.O. Box 123, Broadway, NSW 2007, Australia

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Corresponding author email: [email protected]

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Abstract 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. Keywords Green infrastructure; green walls; green roofs; sustainable development; urban vegetation 1. Introduction

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The majority of the world's population now lives in cities, and urban populations are densifying and urban areas are expanding faster than any other land-use type (United Nations 2015; Dallimer, 2011). Urbanisation has been linked with a range of negative environmental impacts, such as increased air pollution, stormwater runoff, and urban heat island effects, plus greatly reduced vegetation areas and biodiversity (Berndtsson, 2010; Shwartz et al., 2014; Łopucki and Kiersztyn, 2015). These impacts also have secondary effects, such as increased physical discomfort and health problems, and a greater demand for building cooling, leading to increased energy consumption (Pantavou et al., 2011; Santamouris, 2015; Wang et al., 2015). Consequently, there is a requirement for sustainable practices to be integrated into new and existing developments, to assist in mitigating the detrimental effects of urbanisation (Berardi, 2012). Urban forestry, green infrastructure (GI) and, in particular, living greenery integrated into building design, including green wall and green roof (GWGR) projects, are gaining in

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popularity. They not only help ameliorate problems related to urban expansion, but may also avoid the need for re-allocation of scarce land from other urban developments, as is the case with urban forestry and dedicated green space. Additionally, the provision of GWGRs may overcome some of the urban green-space planning challenges identified in cities undergoing densification (Haaland and van den Bosch, 2015). A diverse range of benefits are associated with GWGRs, including a reduction in the urban heat island effect (Busato et al., 2014; Doick et al., 2014; Tan. et al., 2015; Zhang et al., 2015); reductions in building energy consumption (Yang et al., 2008; Getter et al., 2009); enhanced air quality (Nowak et al., 2006); increased biodiversity (MacIvor and Lundholm, 2011; Cook-Patton and Bauerle, 2012, Williams et al., 2014); and improved storm water management (Rowe 2011). GWGRs can also reduce noise pollution (Sheweka and Magdy, 2011; Van Renterghem et al., 2015); facilitate greater urban food production (Orsini et al., 2014); and provide social (Harris, 2009), psychological (Igarashi et al., 2015), and biophilic gratification (Brown and Grant, 2005). Over the last two decades, GWGR technology has been widely implemented in North America and Western Europe, mainly through retrofitting of existing buildings (Williams et al., 2010). Government instruments and support provided through financial incentives, policies and standards, appear to be driving the increase in projects. For example, Stuttgart, Germany, has employed a combination of GWGR policies and subsidies which have led to the creation of an estimated 2 km2 of green rooftops (Claus and Rousseau, 2012). In contrast, GWGR technology has been much less frequently implemented in Australia. This can be attributed to a number of constraining factors, such as a lack of standards for construction/ installation; limited numbers of potential installers; a lack of awareness resulting from few effective examples to give building designers confidence in the value of the technology; and the perception that little research or information is available associated with the technology within climates such as experienced in Australia (Williams et al., 2010). This trend notwithstanding, GWGR projects have increased in frequency in Australia in the past 5 years, although it has hitherto been unknown whether presence, absence, or type of governmental policy influences the take-up rates. Certain local councils in Australia, principally the City of Sydney but also Melbourne, Lane Cove and several others, have been attempting to encourage GWGR uptake, by implementing various policies and guidelines with the objective of reducing or overcoming the constraining factors to GWGR uptake specific to Australia. Whilst the efforts of these councils are aimed at supporting and encouraging the uptake of GWGR projects within their local areas, no overall assessments have previously been undertaken of these policies and, more importantly, whether or to what extent these policies have had a positive effect on GWGR uptake. The current research represents the first study to determine systematically the distribution and developments of GWGR projects throughout Australia. The objectives of this survey were to:

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1. Determine the presence, distribution and abundance of GWGR projects in the major cities of Australia.

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2. Compare GWGR density within and among the major cities.

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3. Explore whether relevant local government policy instruments are associated with increased uptake of GWGRs projects for the city studied.

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4. From the evidence obtained, compare the most successful projects in Australia and abroad, with recommendations for future policy development and urban uptake.

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2. Methods

2.1 Sample areas

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In Australia, the main authorities regulating urban development and thus policies relating thereto, is local government, referred to as councils. Local government is the closest tier of government in local communities throughout Australia, which is not necessarily the case elsewhere internationally. Councils deal with land management, land-use planning, policy development, and development control. Council areas vary widely in population, budget, total area and social conditions. The councils selected for this study form the greater metropolitan regions of the mainland State capital cities (listed here in order of decreasing population numbers): Sydney (New South Wales); Melbourne (Victoria); Brisbane (Queensland); Perth (Western Australia); and Adelaide (South Australia). A total of 100 local government areas were contacted through the course of this study. However, although all councils were assessed within all these cities, a stratified systematic sampling regime was employed for Sydney, since it represents the largest number of councils, approximately 38, of which 20 were sampled. Further, the Perth councils representing Belmont, Bayswater and Swan, Bassendean Mundaring and Kalamunda were consolidated into the Eastern Metropolitan Regional Council, as a coalition of these councils represents a working local governmental council. 2.2 Data collection

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All data were collected between August and October 2015. The data gathered fell into two categories: - individual GWGR projects - local government area green infrastructure policies

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Data gathered on individual GWGR projects were obtained through a combination of email correspondence and semi-structured telephone interviews with participating manufacturers and installers, in addition to general internet searches. The location of each project was identified in order to assign it to a local government area. GWGR companies and their projects were identified through a variety of means, with general internet searches, recommendations from council Environment and Sustainability Departments, from Australian case study databases appearing in Living Architecture: Green Roofs and Walls (Hopkins and Goodwin, 2011) and on the Green Roofs Australasia website (GRA, 2015). This methodologyis by no means exhaustive. However, due to the scarcity of information available in this field, this was the most comprehensive strategy available at the time, to allow the drawing or adequate relative comparisons. Data on local government area policy information was obtained using a similar process, ie. using a combination of reviewing publicly available information on council websites, conducting semi-structured telephone interviews with council Environment and Sustainability or Development and Planning Departments, and emailing council staff members. A script was utilised in order to standardise the email inquiries and telephone interviews (see supplementary data). For this survey a broad spread of policy instruments were identified, and included council policies and written strategies regarding GWGRs; evidence of direct funding for projects; guidance documents for implementation; whether GWGRs were incorporated into wider green space policies (eg. green infrastructure, urban

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forestry, and storm water management); and the existence of projects on council property as a “demonstration of leading by example”. This information was converted to categorical data, and is presented in Table 1. Four GWGR policy categories were created, as follows; whether Council: (1) had GWGR-specific policy and/or funding; (2) offered any guidelines or guidance, but with no specific policy in place; (3)incorporated GWGR ventures into other policies, such as general green infrastructure policy; stormwater management or ecologically sustainable development policy; (4) provided no policies, support or guidance on GWGRs.

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The number of projects in each capital city was also scaled on a per 100,000 capita basis, to reduce effects of city size. The population of each city was obtained by summing the populations from all local government areas sampled from that city’s greater metropolitan area. In order to determine whether relevant local government policy instruments in Australia have increased the uptake of GWGRs, only councils that had at least one project were incorporated into our analysis (Fig. 3). Similarly, if a council had a policy instrument in place, although with no current or explicitly planned projects, it was also included (Fig. 3). Further, statistical associations between policy frequency and project uptake on a city basis were made, using Pearson product moment correlations (Minitab 15.0, Minitab Inc, 2006). Once policy and project data were identified across Australia, a survey of relevant successful international policies was undertaken, with the aim of obtaining an adequate cross section of policies abroad. To allow comparison of policy instruments, these policies were assessed and summarised along with the most successful policies in Australia. In particular we noted policy name, the mechanism of the policy used to increase GWGR uptake, and briefly noted policy details. A synopsis of these polices is presented in Table 6.

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3. Results

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3.1 Distribution of projects Of the 100 Australian councils assessed, 48 councils had at least one GWGR project. The distribution of projects was heavily skewed towards the central council of each city. For all Australian capital cities, the most central council incorporating the city’s Central Business District (CBD) contained the greatest number of GWGR projects within each city (Table 1– 5). The highest number of GWGR projects was identified in the City of Sydney Council, with a total of 123 (Table 1), followed by Brisbane City Council with 82 (Table 2), the City of Melbourne Council with 28 (Table 3), and Adelaide City Council with 13 (Table 4) and the City of Perth Council with 7 (Table 5). Sydney, Australia’s largest and most populous city, had the most GWGR projects of any Australian capital city, followed by Melbourne and Brisbane respectively (Table 1-5, Fig. 1). Perth and Adelaide had notably fewer GWGR projects than the other three cities. This general trend was observed when the data was considered per 100,000 capita, except for Brisbane, which surpassed all cities in the number of GWGR projects per capita (Fig. 2). Adelaide and Perth had fewer projects than other capital cities both in absolute numbers and per capita.

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3.2 Distribution and effect of policies With reference to policy instruments, only one Council (City of Sydney, 2014), offered a policy directly relating to GWGRs. The purpose of its Green Roofs and Walls Policy stated that such installations - “provide numerous social, environmental and cultural

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benefits and contribute to making the City…a more climate change resilient, liveable, beautiful city”. The list of expected benefits was wide-ranging, including both environmental and socio-aesthetic elements/considerations: -slowing and filtering stormwater; -reducing impacts of the Urban Heat Island effect; -creating additional space for urban greening, public and private; -improving air quality; -increasing absorption of carbon dioxide; -improving amenity and liveability of city; -increasing habitat to support biodiversity; -improving building efficiency through heating, cooling and sound insulation; -improving efficiency of solar panels; -extending roof life

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Nine councils offered guidance for the implementation of GWGR, while 19 councils had no separate GWGR policy but it was referred to, or incorporated as part of, wider green space or sustainability policies. The large majority, 71 councils, had no policy instruments for such projects. Conversely, it was found that the number of GWGR projects within a council area was closely related to the presence of a GWGR policy at the local government level (Table 1-5, Fig. 3). Australia-wide, the average number of GWGR projects was higher in councils that offered GWGR policy assistance than in those that did not provide any support, or have any GWGR examples on council buildings etc. The volume of projects was associated with policy frequency per city (r=0.851).

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3.3 International policies For each capital city, the most notable and comprehensive GWGR policy was identified, and compared to some of the most successful international policies, which are summarised in Table 6. Evidently, most polices overseas provide financial incentives, or require mandatory GWGR for certain developments (Table 6). In Australia, this is not the case, with most policies, even the ones deemed successful, providing only limited guidance on the installation and maintenance of GWGR projects, without overcoming high costs associated with GWGR, which has been noted as a major barrier to development (Williams et al. 2010). Comparatively, cities in Europe have considerably more advanced and direct policy instruments for the encouragement of GI technology, with the most successful operations generally making green roofs mandatory for new developments or providing financial incentives. Copenhagen, Denmark, is integrating green roofs as part of its urban development strategy, mandating that green roofs are constructed on all municipal buildings. Basel Switzerland, is similarly mandating green roofs on all new and renovated flat roofs, through the city’s Building and Construction Law. Support for this initiative was further strengthened with subsidies at a rate per area of green roof. These initiatives were bolstered with research grants for innovation and technology advancement of green roofs and supporting competition awards for the industry. Although Stuttgart, Germany has a considerable history of focused interest and culture in GI, yielding a long history of green roof policies. The City of Stuttgart nonetheless, does provide financial support for green roofs through the German Building Code. London, in the United Kingdom, alternatively, provides mainly guidance and management strategies for green roof implementation. Some of the City of London’s policy instruments in regards to GWGRs overlap, as they are incorporated into multiple strategic resolutions e.g. within London’s Response to Climate Change 2015, Biodiversity Action Plan 2010-2015, Green Roof Case Studies 2011 and Green Roof Map 2013.

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In North America, similar policies are also in place, in some scenarios all new developments of a certain specification are required to incorporate a minimum ‘greened’ area or financial incentives exist such as density credits, which are used to encourage green roof development. In Canada, the City of Toronto introduced the Green-Roof bylaw mandating green roofs on all new commercial, institutional, and residential developments with a gross floor area of 2000 m2 or more. From 2012, the bylaw additionally applied to industrial developments. To accompany this law, eligible projects received CAD $75/m2 up to $100,000. In Chicago, USA, a range of strategies are in place, including, but not limited to; Green Roof Grant Program 2005, Green Roof Improvement Fund 2006, Sustainable Development Policy 2007, Adding Green to Urban Design Plan 2008, and Green Permit Benefit Tier Program 2015,. Through these instruments, the city encourages green roofs through both financial and non-financial incentives, with reduced permit fees or priority development review. Additionally, cities like Vancouver, Canada, and Los Angeles, California mandate that some new buildings are required to meet sustainability qualifications such as the Leadership in Energy and Environmental Design (LEED) standards, into which green roofs and green walls are incorporated. In Asia, different drivers such as urban densification processes leading to the loss of urban green space has expedited efforts to implement GI. In Hong Kong, comprehensive guidelines are in place design, detailing plant selection, installation, maintenance, and costing tools for intensive and extensive green roofs. Government policy encourages green roofs on public buildings. Policies JPN1 and JPN2 promote green features by exempting communal ‘sky’ gardens from gross floor area and site coverage taxes, thus providing economic benefit to the developer. The Republic of Singapore utilises financial incentives to reduce cost barriers to industry, through The Skyrise Greenery Incentive Scheme (SGIS) released in 2009, which funds up to 50% of the costs of installation of green roofs. In Tokyo, Japan the Tokyo Green Plan 2012 policy; mandates that new private developments of greater than 1000 m2 and public buildings greater than 250 m2 are required to have at least 20% greened roof or incur a US $2000 fine. The Green Building Program 2002 assesses and publishes efforts made by developers to promote green architecture. Japanese National Building Law, 2005 requires all new apartment or office buildings in urban areas to have at least 20% vegetated rooftops. Although Australian policies relating to building and development mainly occur within the local council jurisdiction, many international examples relating to GWGR policies occur at other jurisdiction levels. For example, in Basel, Switzerland, GWGR policy occurs at the canton level (Brenneissen, 2008); Singapore provides financial incentives on a national scale (National Parks Board, 2016); and Chicago, USA, has GWGR policy at the city level (City of Chicago 2008). City wide, state wide, canton/council wide or even nation-wide policies occurring in international examples may be more successful due to greater funding as well as promoting increased awareness across a greater spatial scale. Additionally, in countries where the green roof industry is well established, there are non-government registered voluntary associations that communicate research and credential technical standards or provide certification for demonstrated specific building attributes including for the construction of green roofs e.g. Dachgartner-Verband Deutscher e.V. and, Forschungsgesellschaft Landschaftsentwicklung Landschaftsbau e.V. (FLL) in Germany.

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4. Discussion It has been noted that there has been a limited implementation of GWGRs within Australia relative to many other Western countries (Williams et al., 2010). The investigation reported here is the first study that has quantified the abundance and distribution of GWGRs

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across capital cities in Australia. It was interesting to find that, within each capital, the distribution of GWGR projects was highly variable (Table 1). For each capital, the most central Council encompassing a CBD had the highest number of GWGR projects for that city, so that the distribution of GWGR projects appears to be related to the intensity of urbanisation within a council’s area. In addition, this trend was still apparent when GWGR project density was calculated on a per capita basis. As urbanised areas tend to have the most limited existing greenspace, along with the greatest population density, this trend is not surprising. The most viable method for improving urban greening in future is likely to be through its incorporation onto existing or newly built infrastructure. The use of GWGR as symbols of institutional prestige or status cannot be discounted as a possible contributor to their greater density in the inner city, as this is also the location of many high profile businesses. Despite increasing popularity, GWGR technology in Australia is still in its developing stages, and the various ecological and environmental services the technology can provide may not as yet be widely understood. There are concerns that high profile GWGR projects may simply be costly showcase examples, designed principally for their aesthetics and with less appreciation of their potential environmental benefits. They are sometimes described as “green blingor “eco bling” (Wilkinson and Dixon, 2016). These examples suggest that the drivers of GWGR adoption in Australia may differ from those in the northern hemisphere, where environmental benefits may be a stronger driver for GWGR deployment, rather than of aesthetic or amenity concerns. The uptake of GWGR in Switzerland, for example, is explicitly aimed at: increasing biodiversity; replacing lost habitat; saving energy spent on thermal regulation in the building; and providing stormwater retention (Brenneissen, 2008). In Australia such further incentives may be required to encourage more ecologically or environmentally targeted investment in GWGRs (Dover, 2015), in order to more rapidly accrue the associated environmental consequences, and not rely on the attraction of aesthetic benefits alone. Our evidence indicates that to date there have been large differences in GWGR uptake across Australia’s mainland state capitals (see Fig. 1 and Fig. 2). Williams et al. (2010) proposed that GWGR uptake Australia wide has been impeded by a lack of scientific data available to evaluate their suitability to local conditions. International examples suggest that climate-specific plant selection is paramount to the success of GWGR projects (Perkins and Joyce, 2012). Research and case study examples of species selection from Europe and North America are thought to be largely inapplicable to Australia, except for the most general principles, because of both geographic and local regional climatic differences, available plant species of known resilience, and substrate variables. For example, the succulent genus Sedum (Fam. Crassulaceae), used widely in roof gardens in northern hemisphere cool temperate regions (e.g. England), is unlikely to be able to cope with the warm to hot humid summer conditions experienced in many areas of Australia (e.g. in Brisbane; Sydney; Melbourne) (Perkins and Joyce, 2012). Recently, the number of overseas studies relating to the climatic suitability of GWGR species has increased significantly, along with an increasing awareness in the general public of the value of GWGR projects (Perez-Urrestarazu et al., 2016). This increase in awareness is also now occurring across all potential stakeholder levels in Australia, reflected in the implementation of the small number of showcase examples now installed, showing that they can act as successful precedents to a somewhat risk-averse industry (Perkins and Joyce, 2012. However, they alone do not explain the disparities in GWGR uptake across the capital cities. Australia is a geographically large country with long distances between capital cities, which have quite distinct climates. Most Australian cities have hot, dry summers. The most extreme summer conditions are found in Adelaide and Perth, with rainfalls of only 63 mm and 34 mm

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respectively, plus average maximum temperatures of 25-30oC, with a few days in each city usually reaching more than 40oC (Dec–Feb) (Aust. Bureau of Meteorology, 2016). Brisbane also has an average maximum summer temperature of 30oC, but an average summer rainfall of 458 mm (Bureau of Meteorology, 2016). Plant hardiness plays a key role in enabling environmental benefits whilst maintaining the aesthetic value of a GWGR project (PerezUrrestarazu et al., 2016). Also the often shallow substrate depth of GWGR installations limits their water storing capacity, potentially making the vegetation more susceptible to water stress during periods of little rainfall (Fioretti et al., 2010; Gray, 2016). The lack of research and limited effective examples of GWGRs in climates with hot dry summers poses challenges in constructing and maintaining GWGR gardens that can survive these conditions without excessive irrigation requirements (Simmons, 2006). The use of large volumes of water to facilitate plant survival during dry periods provides a dilemma for most of Australia: it may be considered financially and environmentally unsustainable, and politically objectionable, during times of water scarcity in our cities (Williams et al., 2010). In these cities, further research regarding the use of drought tolerant species, and the logistics of recycled or grey water use, are therefore also needed to allow GWGR uptake to prosper in areas regularly affected by water shortages. On the other hand, the climatic conditions of Brisbane may allow GWGR development to borrow research and development from international wet-climate precedents from Southeast Asia, such as Singapore, because of their climatic similarities (e.g. Wong et al., 2005), Whilst it may be a reasonable assumption to expect the number of GWGR projects to increase proportionally with the city’s population (Fig. 1), this does not appear to be the case in this survey, with Brisbane (Australia’s third most populous city) having the most projects per capita (Fig. 2). This trend could be due to an increased sense of corporate social responsibility in the area, as particular businesses have a desire to appear environmentally aware and sustainable, which could have had a flow-on effect with competitors and other businesses emulating the efforts of the originating organisations. Policy instruments and mechanisms related to GWGRs are a major factor worldwide in influencing the abundance and distribution of GWGRs (Carter and Fowler 2008; Connop et al., 2016). In Australia, policy support is most likely to come from local government (Stenhouse, 2004), as it is this level of government that is responsible for functions relating to land management, land-use planning, policy development, and developmental control at the relevant scales. In the current investigation, across all capital cities, the presence of a policy strategy and document relating to GWGRs at council level was associated with a higher average number of GWGR projects per council than for those which had no policies (Fig. 3). Perth, however, had no councils with any policy relating to GWGR. The introduction of policies relating to GWGRs by local government can assist in lowering barriers to their use, replicating the successful approaches of overseas cities (Table 6). Although the broad definition of policy used in this study may reflect varying levels of support from local councils, all types of support appear to have had a positive effect, leading to greater GWGR uptake. Such council support may also be in the form of a GWGR project on a council building, which can increase awareness and provide an example demonstrating that GWGRs can be successfully developed and maintained in an Australian context. More comprehensive examples of policy include technical guides based on scientific research, an introduction of standards, and financial incentives (such as those provided by the City of Sydney Council). This evidence suggests that the introduction of an encouraging and usable policy, and increased support from local government, are effective means to promote the development of GWGR projects by assisting in overcoming the barriers to uptake. The work conducted by several councils across Melbourne exemplifies this approach. Although no council in Melbourne has a direct policy, the collaboration of four Melbourne councils with

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the State of Victoria and the University of Melbourne, has produced a comprehensive guideline known as the Growing Green Guide. The Growing Green Guide assists the councils of Greater Melbourne overcome many of the barriers that limited GI uptake as outlined by Williams et al. (2010) and therefore may have played a key role increasing the average GI uptake across these councils. Interestingly Adelaide City Council also offers guidelines regarding GI, however in comparison to the Growing Green Guide, Adelaide City Council’s Green Infrastructure Guidelines offers rather limited guidance on the installation and maintenance of GI, only briefly delving into the benefits, design considerations and maintenance considerations (Adelaide City Council 2014). A key difference between the guides is the lack of detailed case studies in a local context that are essential to provide confidence, increase awareness and reveal successful examples in a local climate (Williams et al. 2010). These differences in detail between the two guidelines may reflect the GI uptake in each city, as well as public awareness and comprehension of GI, however, as each of these guidelines were introduced in 2014, it is still too early to definitively measure their success. Although the Growing Green Guide was produced by a limited collaboration, it is publicly available, easily accessible and can be generalised for use across Melbourne and Victoria. Because of the availability of this information, the benefits offered by these guidelines are extended towards all councils of the Greater Melbourne region, and although this document may have national and even international relevance, its widespread application may be limited due to differences that arise across larger geographic scales such as differences in building regulations, and different plant selections due to different climates. Policy makers in numerous international cities have demonstrated increased density of GWGR projects subsequent to the implementation of strategies aimed at increasing GWGRs, with the most direct methods being through the creation of legislation requiring buildings to adopt GWGRs. For example, the City of Toronto introduced a bylaw requiring a portion of new buildings or new building additions with a gross floor area of 2000 m2 or greater, to include a green roof (City of Toronto, 2016). This approach has also been utilised across Germany, where the Federal Building Code authorises German Municipalities to mandate green roofs on all new flat-roofed buildings, via binding land use plans (Mees et al., 2013). Stuttgart has also implemented this strategy across some parts of the city, along with offering ‘density bonuses’ for developers on a case-by-case basis, leading to the creation of 2.2 million m2 of green rooftops in Stuttgart (Claus and Rousseau, 2012). This trend notwithstanding, Stuttgart has a long history of green roof policies, having first integrated green roofs into the cities local development plans in 1985. Switzerland is another international leader in GWGR uptake, with the Canton of Basel considered to be the pioneer in Switzerland’s GWGR adoption. GWGR development has been achieved through incentive schemes funded by governmental policy, research grants, legislature, and contests (Carter and Kazmierczak, 2010). In 2002, Basel’s building and construction law mandated green roofs on all new and renovated flat roofs (Carter and Kazmierczak, 2010). By 2008, Basel boasted 1929 green roofs (Brenneissen, 2008), and by 2010 there was over 1 million m2 of green roofed area within the canton (Brenneisen, 2012). The success of these policy mechanisms is clear, since Basel has the highest area of green roofs per capita in the world (Carter and Kazmierczak, 2010). Some cities make use of direct financial incentives, subsidies, and rebates. Singapore, for example, utilises financial incentives to reduce cost barriers to industry, through The Skyrise Greenery Incentive Scheme (SGIS), which funds up to 50% the costs of installation of green roofs. This scheme has already seen an increase of 110 projects within 2015. As of 2014, Singapore has 61 ha of greenery covering the exterior of its buildings - one of the highest rates among cities in the world (National Parks Board, 2016). The City of Portland and the City of Seattle both incorporate a Floor Area Ratio (FAR) bonus that offers

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developers construction-based incentives for the integration of GRs in all new developments. The outcome of these incentives has led to a total of 436 eco-roofs in Portland covering almost one million square feet of rooftop as of August 2014, and 62 green roofs in Seattle covering a vegetated area of 359,375 square feet as of December 2009. Comparatively, San Francisco provides financial incentives through decreased rates for properties with GRs. In 2013, 8 of 78 projects submitted for review included a green roof, with a total 139,000 square feet of green roof construction. New York City currently provides tax abatements of $4.50 per square foot of building-integrated green space. As evidenced by these international examples, it would appear that direct supportive policy will always have a positive effect in encouraging the uptake of GWGRs. However, the policy instrument has to be developed for the jurisdiction in which it will be implemented, and will vary depending on location and goals of the jurisdiction (Carter and Fowler, 2008). Similarly, certain direct approaches might be infeasible from a financial or political stand point, particularly in cities that are fiscally conservative. In these cities, indirect incentives may be more appropriate (Brudermann and Sangkakool, 2017). For example, The City of Seattle utilities indirect incentives in the form of listing green roofs as an option for the Seattle Stormwater Code. The code requires storm-water filtration and retention of run-off which can be achieved through the installation of green roofs. Whilst London encourages GWGRs through a number of policy instruments, the city’s Biodiversity Action Plan 20102015 seeks to identify ways in which green roofs, walls and balconies could be utilised to maximise their benefit to wildlife. This form of indirect motivation has had a marked effect with 678 GRs constructed in central London by 2013.In countries where the green roof industry is well established, there are in some instances non-government registered voluntary associations that provide certification for the construction of green roofs e.g. DachgartnerVerband Deutscher e.V. and, Forschungsgesellschaft Landschaftsentwicklung Landschaftsbau e.V. (FLL) from Germany and the Leadership in Energy and Environmental Design (LEED) in the United States of America. Vancouver, Canada, is one of those cities that is heavily reliant on the knowledge and expertise of organisations such as these for installation and maintenance of GWGRs; all new building rezonings are required to meet the LEED Gold standard. Equivalently, the City of Los Angeles Department of Public Works’ Green Building Program states that all non-residential buildings over 10,000 ft2 and largescale residential buildings must meet LEED certifications. As stated in Melbourne’s Growing Green Guide, industry credentialing systems in Australia, such as Building Code of Australia, Green Building Council of Australia Star system, or National Australian Built Environment Rating System (NABERS) could be the driving force to develop guidelines, codes and standards for green roofs, walls or façades. If this can be achieved, policy in Australia could focus on making new developments meet these standards, analogous to those North American cities that mandate new buildings must meet sustainability qualifications such as LEED. This weight of evidence suggests that further policy implementation in Australia could increase GWGR deployment. Additionally, consideration needs to be given to the planning and implementation of local government policies for maximum success. In Australia nation-wide policy instruments may not prove feasible, because of differing climates and other drivers of uptake. Whilst policy appears to be the most effective means of increasing GWGR uptake, it should be noted that the introduction of a policy is in this case often preceded by research in a local context, along with pilot trials and other case studies that can increase awareness, understanding of the issues, and consumer confidence. The guidebook Green Roofs, A Resource Manual for Municipal Policy Makers (Lawlor et al., 2006), describes six phases in policy establishment: introduction and awareness; community

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engagement; action plan development and implementation; technical research; program and policy development; and continuous improvement. It should be noted that most policies explored in this study were exclusively relevant to green roofs. Whilst it was not the main objective of this study to differentiate between green roof or green wall projects, nor differentiate between policies aimed at the different project types, the authors propose that green roof policy is more readily adopted and administered as they are less problematic to legislate as mandatory, green roof research is more abundant, and green roofs provide an amenity potentially utilised by more stakeholders than as is the case for green walls. The study presented here is the first attempt to quantify GWGR projects across Australia’s largest cities, and explore factors that influence the distribution and uptake of GWGRs. Not all GWGR projects across could be pursued or recorded, and indeed GWGRs and various other landscape features can be hard to differentiate. Additionally, there is a lot of variation within Australian local government areas, reflecting multiple different social conditions, political conditions, resource capacity, climates, urban landscapes, and usage profiles relating to business districts, semi-residential and residential areas. However, our investigation revealed that our Australian capital cities are in various stages of developing their GWGR sectors. It would seem that Sydney is the most advanced, with Melbourne and Brisbane following closely. However, the evidence indicates that, prior to the accomplishment of “successful establishment” phase, i.e, prior to “policy introduction”, the community may well express doubts and objections with respect to any proposed new greening regulations, and to the perceived likely success of such individual projects. The success of the policy in increasing GWGRs may be lengthy in realisation of the benefits (Carter and Fowler, 2008).

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The distribution of GWGR projects within Australia is highly varied among the capital cities. Variation between cities may be based on unique barriers to GWGR uptake, and stage of development of the GWGR installation and maintenance sector. These barriers may include a lack of standards and a general absence of green infrastructure policies, relatively few professionals capable of installing the technology, a lack of awareness with few successful examples to give urban designers confidence, and little research associated with GWGRs within the climates that each Australian city experiences. Within each city, the distribution of GWGR projects was also highly varied. Distribution of GWGR projects within cities was related to the degree of local urbanisation of each council; with inner city councils having a greater density of GWGRs, however there are likely to be a multitude of external forces driving the distribution of projects. This suggests that the drivers for GWGR uptake tend to vary within cities, and a variance in the barriers to GWGR uptake occurs between cities. The existence of relevant policy instruments are associated with more GWGR projects in Australia. Based on the successful examples seen internationally, especially those that provide financial incentives or make these type of projects mandatory for certain new developments, further policy implementation in Australia could increase GWGR deployment. Currently, policy instruments related to GWGR projects are infrequent, with only limited institutional guidance on applicability, installation and maintenance. It is apparent from the literature presented here that any initiative, whether it be legislative or financial will have positive outcomes in regards to increasing the frequency of these project implementations. Clearly, the proven successful model demonstrated in the regionally relevant city of Singapore, including both financial incentivization and legislation, has led to a substantially higher uptake rate. Expanding and developing the awareness at the local government level is

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likely to be key to drafting and driving such policy within Australia. If this can be achieved, tangible demonstration of the benefits of GWGR technology may be realised, and Australia may follow the examples set by the long standing benchmark countries such as Germany and Switzerland. References

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Berardi, U., 2012. Sustainability Assessment in the Construction Sector: Rating Systems and Rated Buildings. Sustainable Development, 20, 411-424. Berndtsson, C.J., 2010. Green roof performance towards management of runoff water quantity and quality: A review. Ecological Engineering, 36, 351-360. Brenneisen S., 2006. Space for urban wildlife: Designing green roofs as habitats in Switzerland. Urban Habitats, 4 27-36. Brown, C.,Grant, M., 2005. Biodiversity and human health: What role for nature in healthy urban planning? Built Environment, 31 326-338. Brudermann, T., Sangkakool, T., 2017. Green roofs in temperate climate cities in Europe – An analysis of key decision factors, Urban Forestry & Urban Greening, 21 224-234. Busato, F., Lazzarin, R., Noro, M., 2014. Three years of study of the Urban Heat Island in Padua: Experimental results. Sustainable Cities and Society, 10, 251-258. Australian Bureau of Meteorology. 2015. http://www.bom.gov.au/australia/index.shtml. Accessed August 2015 – September 2015. Carter, T., Fowler, L., 2008. Establishing Green Roof Infrastructure Through Environmental Policy Instruments. Environmental Management, 42 151-164. City of Chicago., 2008. Adding green to urban design a city for us and future generations. City Plan Commission. https://www.cityofchicago.org/dam/city/depts/zlup/Sustainable_Development/Publications/Green_Urban_Desig n/GUD_booklet.pdf Accessed January 2017. City of Sydney., 2014. Green Roofs and Walls Policy, City of Sydney. In: City of Sydney2030. City of Sydney., 2013. Green Roofs and Walls Perception Study – Final Report and Recommendations'. City of Toronto., 2016. ‘Green Roofs’. City planning division, http://www1.toronto.ca/wps/portal/contentonly?vgnextoid=3a7a036318061410VgnVCM10000071d60f89RCR D Accessed January 2016. Claus, K., Rousseau, S., 2012. Public versus private incentives to invest in green roofs: A cost benefit analysis for Flanders. Urban Forestry and Urban Greening 11, 417-425. Cook-Patton, S. C. Bauerle, T.L., 2012. Potential benefits of plant diversity on vegetated roofs: a literature review. Journal of Environmental Management 106, 85-92. Connop, S., Vandergert, P., Eisenberg, B., Collier, M.J., Nash, C., Clough, J., Newport, D., 2014. Renaturing cities using a regionally-focused biodiversity-led multifunctional benefits approach to urban green infrastructure. Environmental Science & Policy 62, 99-111. Dallimer, M., Tang, Z., Bibby, P.R., Brindley, P., Gaston, K.J. Davies, Z.G., 2011. Temporal changes in greenspace in a highly urbanized region. Biology Letters 7, 763-766. Doick, K. J., Peace, A., Hutchings, T.R., 2014. The role of one large greenspace in mitigating London's nocturnal urban heat island. Science of the Total Environment 493, 662-671. Fioretti, R., Palla, A., Lanza, L.G Principi, P., 2010. Green roof energy and water related performance in the Mediterranean climate. Building and Environment 45, 1890-1904. Getter, K. L., Rowe, D.B., Robertson, G.P., Cregg, B.M, Andresen, J.A., 2009. Carbon sequestration potential of extensive green roofs. Environmental Science and Technology 43, 7564-7570. Gray, T., 2016. Issues in Green Infrastructure. New York, Nova Science Publishers. Green Roofs Australaisia., 2015 https://greenroofsaustralasia.com.au/. Accessed August 2015 – September 2015). Haaland, C., van den Bosch, C., 2015. Challenges and strategies for urban green-space planning in cities undergoing densification: a review. Urban For. Urban Greening 14, 760–77. Harris, E., 2009. The role of community gardens in creating healthy communities. Australian Planner 46 24-27. Heusinger, J. Weber, S., 2015. Comparative microclimate and dewfall measurements at an urban green roof versus bitumen roof. Building and Environment 92, 713-723. Hopkins, C., Goodwin, G., 2011. Living Architecture: Green Roofs and Living Walls. Collingwood, Melbourne. CSIRO Publishing.

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Igarashi, M., Aga, M., Ikei, H., Namekawa, T., Miyazaki, Y., 2015. Physiological and Psychological Effects on High School Students of Viewing Real and Artificial Pansies. International Journal of Environmental Research and Public Health 12, 2521-2531. Lawlor, G., Currie, B., Doshi, H., Weiditz, I., 2006. Green Roofs: A Resource Manual for Municipal Policy Makers. Canada Mortgage and Housing Corperation. Mees, H.L., Driessen, P.P., Runhaar, H.A. Stamatelos, J., 2013. Who governs climate adaptation? Getting green roofs for stormwater retention off the ground. Journal of Environmental Planning and Management 56, 802-25. Łopucki, R. Kiersztyn, A., 2015. Urban green space conservation and management based on biodiversity of terrestrial fauna – A decision support tool. Urban Forestry and Urban Greening 14, 508-518. MacIvor, J.S., Lundholm, J., 2011. Insect species composition and diversity on intensive green roofs and adjacent level-ground habitats. Urban Ecosystems 14, 225-241. National Parks Board., 2016. https://www.nparks.gov.sg/news/2009/4/a-lusher-and-greener-singapore-ura-andnparks-introduce-schemes-to-promote-skyrise-greenery 11_vertical_garden_city_sg.aspx Accessed August 2016. Nowak, D.J., Crane, D.E., Stevens, J.C., 2006. Air pollution removal by urban trees and shrubs in the United States. Urban Forestry and Urban Greening 4, 115-123. Orsini, F., Gasperi, D., Marchetti, L., Piovene, C., Draghetti, S., Ramazzotti, S., Bazzocchi, G., Gianquinto, G., 2014. Exploring the production capacity of rooftop gardens (RTGs) in urban agriculture: the potential impact on food and nutrition security, biodiversity and other ecosystem services in the city of Bologna. Food Security 6, 781-792. Pantavou, K., Theoharatos, G., Mavrakis, A., Santamouris, M., 2011. Evaluating thermal comfort conditions and health responses during an extremely hot summer in Athens. Building and Environment 46, 339-344. Pérez-Urrestarazu, L., Fernández-Cañero, R., Franco, A., Egea, G., 2016. Vertical Greening Systems and Sustainable Cities. Journal of Urban Technology 22, 65-85. Perkins, M., Joyce, D., 2012. Living Wall and Green Roof Plants for Australia. Royal Industries Research and Development Corporation. Canberra, Australian Government. RIRDC Publication No. 11/175 Rowe, D.B., 2011. Green roofs as a means of pollution abatement. Environmental Pollution 159, 2100-2110. Santamouris, M., 2015. Analyzing the heat island magnitude and characteristics in one hundred Asian and Australian cities and regions. Science of The Total Environment 512, 582-598. Sheweka, S. Magdy, A.N., 2011. The living walls as an approach for a healthy urban environment. Energy Procedia 6, 592-599. Shwartz, A., Turbé, A., Simon, L., Julliard, R., 2014. Enhancing urban biodiversity and its influence on citydwellers: An experiment. Biological Conservation 171, 82-90. Stenhouse, R.N., 2004. Local government conservation and management of native vegetation in urban Australia. Journal of Environmental Management 34, 209-22. Tan, Z., Lau, K.K.-L., Ng, E., 2015. Urban tree design approaches for mitigating daytime urban heat island effects in a high-density urban environment. Energy and Buildings 114, 265–274. United Nations., 2015. Population Division World Population Prospects The 2015 Revision. Department of Economic and Social Affairs. https://esa.un.org/unpd/wpp/publications/files/key_findings_wpp_2015.pdf. Accessed January 2017. Van Renterghem, T., Forssén, J., Attenborough, K., Jean, P., Defrance, J., Hornikx, M., Kang, J., 2015. Using natural means to reduce surface transport noise during propagation outdoors. Applied Acoustics 92, 86-101. Wang, Y., Berardi, U., Akbari, H., 2015. Comparing the effects of urban heat island mitigation strategies for Toronto, Canada. Energy and Buildings 114, 2-19. Wong, N. H., Wong, S.J., Lim, G.T., Ong, C.L., Sia, A., 2005. Perception Study of Building Professionals on the Issues of Green Roof Development in Singapore. Architectural Science Review, 48, 205-214. Wilkinson, S.J., Dixon, T., 2016, Green Roof Retrofit Building Urban Resilience, John Wiley & Sons. ISBN: 978-1-119-05557-0 Williams, N. S., Lundholm, J., Scott-MacIvor, J., 2014. Do green roofs help urban biodiversity conservation? Journal of Applied Ecology 51, 1643-1649. Williams, N. S., Rayner, J.P., Raynor, K.J., 2010. Green roofs for a wide brown land: Opportunities and barriers for rooftop greening in Australia. Urban Forestry and Urban Greening 9, 245-251. Yang, J., Yu, Q., Gong, P., 2008. Quantifying air pollution removal by green roofs in Chicago. Atmospheric Environment 42, 7266-7273. Zhang, B., Gao, J., Yang, Y., 2014. The cooling effect of urban green spaces as a contribution to energy-saving and emission-reduction: A case study in Beijing, China. Building and Environment 76, 37-43.

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Fig. 1. The total number of green infrastructure projects in each Australian state capital city’s greater metropolitan area.

679 680 681 682

Fig. 2. The average number of green infrastructure projects per local government area across each Australian state capital city’s greater metropolitan area, scaled to a population size of 100,000.

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Fig. 3. The average number of GWGR projects per local government area across each state capital city of mainland Australia, comparing councils that offered GWGR support to those that did not offer support.

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719 720

Table 1. Sydney’s metropolitan councils with the total number of GWGR projects and type of policy instrument for GWGR ventures. Local Government Area

Total GWGR projects

Policy present*

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721 722 723 724 725 726

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Sydney 123 1 Ku-ring-gai 2 3 Lane Cove 1 2 Bankstown 1 4 Blacktown 1 4 Hurstville 1 4 Kogarah 1 4 Holroyd 0 2 Hornsby 0 2 The Hills 0 3 Ashfield 0 4 Auburn 0 4 Botany Bay 0 4 Burwood 0 4 Camden 0 4 Campbelltown 0 4 Canada Bay 0 4 Canterbury 0 4 Fairfield 0 4 Hunter's Hill 0 4 * 1 specifies that the council had a GWGR specific policy. 2 indicates that there were guidelines or guidance offered by the local council but no specific policy in place. 3 specifies GWGR ventures were incorporated into other policies, such as green infrastructure policy, storm water management or ecologically sustainable development policy. 4 specifies no policies, support or guidance offered.

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726 727 728

Table 2. Melbourne’s metropolitan councils with the total number of GWGR projects and type of policy instrument for GWGR ventures. Local Government Area

Total GWGR projects

Policy present*

729 730 731 732 733 734

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Melbourne 28 2 Stonnington 13 2 Port Phillip 12 2 Yarra 7 2 Boroondara 6 3 Monash 5 3 Manningham 4 4 Greater Geelong 4 4 Frankston 3 4 Yarra Ranges 3 4 Casey 2 4 Greater Dandenong 2 4 Moonee Valley 2 4 Banyule 2 4 Mornington Peninsula 1 3 Glen Eira 1 3 Cardinia 1 4 Whitehorse 1 4 Bayside 1 4 Hobsons Bay 1 4 Maroondah 0 2 Knox 0 4 Kingston 0 4 Wyndham 0 4 Melton 0 4 Brimbank 0 4 Hume 0 4 Maribyrnong 0 4 Moreland 0 4 Darebin 0 4 Whittlesea 0 4 Nillumbik 0 4 * 1 specifies that the council had a GWGR specific policy. 2 indicates that there were guidelines or guidance offered by the local council but no specific policy in place. 3 specifies GWGR ventures were incorporated into other policies, such as green infrastructure policy, storm water management or ecologically sustainable development policy. 4 specifies no policies, support or guidance offered.

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734 735 736

Table 3. Brisbane’s metropolitan councils with the total number of GWGR projects and type of policy instrument for GWGR ventures. Local Government Area

Policy present *

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Brisbane 82 3 Moreton Bay 2 3 Ipswich 2 4 Logan 1 4 Redland 1 4 * 1 specifies that the council had a GWGR specific policy. 2 indicates that there were guidelines or guidance offered by the local council but no specific policy in place. 3 specifies GWGR ventures were incorporated into other policies, such as green infrastructure policy, storm water management or ecologically sustainable development policy. 4 specifies no policies, support or guidance offered.

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Total GWGR projects

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742 743 744

Table 4. Perth’s metropolitan councils with the total number of GWGR projects and type of policy instrument for GWGR ventures. Local Government Area

Total GWGR projects

Policy present*

745 746 747 748 749 750

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Perth City 7 4 Eastern Metropolitan Regional Council (EMRC) 3 4 Stirling 3 4 Subiaco 3 4 Cambridge 1 3 Mosman Park 1 3 South Perth 1 3 Canning 1 4 Fremantle 1 4 Mandurah 1 4 Melville 1 4 Peppermint Grove 1 4 Cockburn 0 3 Cottlesloe 0 3 Gosnells 0 3 Joondalup 0 3 Nedlands 0 3 Swan 0 3 Vincent 0 3 Wanneroo 0 3 Bassendean 0 4 Bayswater 0 4 Belmont 0 4 Claremont 0 4 East Fremantle 0 4 Kalamunda 0 4 Kwinana 0 4 Rockingham 0 4 Serpentine-Jarrahdale 0 4 Victoria Park 0 4 * 1 specifies that the council had a GWGR specific policy. 2 indicates that there were guidelines or guidance offered by the local council but no specific policy in place. 3 specifies GWGR ventures were incorporated into other policies, such as green infrastructure policy, storm water management or ecologically sustainable development policy. 4 specifies no policies, support or guidance offered.

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750 751 752 753

Table 5. Adelaide’s metropolitan councils with the total number of GWGR projects and type of policy instrument for GWGR ventures.

Local Government Area

Total GWGR projects

Policy present*

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Adelaide City 13 2 Norwood Payneham St. Peters 3 4 Charles Sturt 1 4 Adelaide Hills 1 4 Marion 1 4 Burnside 0 4 Mitcham 0 4 West Torrens 0 4 Walkerville 0 4 Unley 0 4 Port Adelaide Enfield 0 4 Campbelltown 0 4 Prospect 0 4 * 1 specifies that the council had a GWGR specific policy. 2 indicates that there were guidelines or guidance offered by the local council but no specific policy in place. 3 specifies GWGR ventures were incorporated into other policies, such as green infrastructure policy, storm water management or ecologically sustainable development policy. 4 specifies no policies, support or guidance offered.

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762 Table 6. GWGR policies for each Australian major city compared to some of the most successful international policies City Policy name Mechanism Policy details Comments Since implementation of green roofs and walls policy in 2014, City of Sydney has experienced 23% increase in total GRGW coverage.

Awareness, guidance

Comprehensive information on GRGW benefits; technical design, installation, maintenance considerations; detailed best practice case studies in Victoria. Leadership through GRGW on council buildings.

Since 2014 release of guidance document, average uptake of GRGW across all Greater Melbourne councils increased.

Awareness, guidance

Document refers to living architecture, green streets, WSUD, urban forests. Section on GRGW, providing brief information

Negligible increase in GRGW uptake since release of guidelines.

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City of Melbourne and 3 other councils endorse the Growing Green Guide 2014 (State of Victoria 2014)

Information on GRGW benefits, barriers to uptake, design considerations. Comprehensive resource manual for GR. Leadership through GRGW on council buildings, establishing advisory committee. Subsidies provided case-by-case through environmental performance grants.

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Melbourne, Australia

Awareness, guidance, financial incentives, GRGW monitoring

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City of Sydney provides Green Roofs and Walls Policy 2014, Green Roofs and Walls Policy Implementation Plan Environmental Performance Grants supported by Sustainable Sydney 2030

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Sydney, Australia

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Adelaide, Australia

Adelaide City Council provides Green Infrastructure Guidelines 2014

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on GRGW benefits, design.

Perth, Australia

No enacted GRGW policies or guidance notes.

Basel, Switzerland

Building and Construction Law (BCL) 1996-97 and 2005-06, BCL 2002

City of Stuttgart 1986 regulations, Climate Atlas 2008 Stuttgart, German Building Code (GBC), FLL Green Roof Guidelines 2008

Awareness, financial incentives

Mention of GR as strategy for climate action in climate change policy, within strategic land use and planning, and research sections. AUD$1000$10000 grants awarded on merit to sustainability projects within Brisbane City Council that reduce energy consumption and greenhouse gas emissions of their facilities.

Strong uptake of GRGW in Brisbane City Council. Unclear if uptake is associated with policy.

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Brisbane City Council provides Plan for Action on Climate Change 2007, and Community Sustainability and Environmental Grants Program

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Brisbane, Australia

N/A

Perth hosts the least number of GRGW projects and the smallest total greened area of all capital cities sampled in Australia.

Awareness, guidance, financial incentives, regulations

BCL 1996-67 and 2005-06 provided subsidies of 20 Swiss francs per m2 of GR. BCL 2002 mandated GR on all new and renovated flat roofs.

In 1998, 10% of flat roofs in Basel had GR. By 2015, over 100 Ha GR in Basel, constituting the largest area of GR per capita in world.

Awareness, guidance, financial incentives, regulations

City of Stuttgart provides financial support for GR. Climate Atlas provides climatic assessments and

Since 1986, City of Stuttgart provided financial support for 6 Ha GR. By 2015, Stuttgart

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Stuttgart, Germany

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Awareness, guidance, regulations

London, UK

City of London provides Living Roofs and Walls 2008 Guidance Note, Green Roofs and Development Site Environs Policy and Urban Greening Policy within London’s Response to Climate Change 2015, Biodiversity Action Plan 2010-2015, Green Roof Case Studies 2011, Green Roof Map 2013

Awareness, guidance, monitoring

City of Chicago provides Adding Green to Urban Design Plan 2008, Green Permit Benefit Tier Program and Green Permit Program 2015, Sustainable Development Policy

Awareness, guidance, financial incentives, regulations, monitoring

By 2012, there were over 40 GR in the City of Copenhagen.

Guides provide comprehensive information on GRGW benefits, costs, maintenance, and case studies. Climate change policies encourage sustainable building design including wildlife sensitive design, and roof, wall, and site planting.

By 2013, 678 GR in central London, measuring over 17.5 Ha.

Various GR projects eligible for reduced permit fees, priority development review, financial, non-financial incentives under different policies.

In 2008, 400 GR covering 37 Ha. By 2010, 509 GR measuring 52 Ha.

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SCCW mandates GR on all municipal buildings. Since 2008, Copenhagen has integrated GR as part of urban development. Since 2010, City of Copenhagen has mandated GR on most new local plans.

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had 30 Ha GR.

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recommendations for planning measures in Stuttgart. GBC mandates implementation of local climate sensitive planning recommendations.

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Guidelines 2008

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Guidance on GR best practices.

All non-residential buildings over 10,000 ft2 and other large-scale residential buildings must meet Leadership in Energy and Environmental Design (LEED) qualifications

Green roofs are incorporated in LEED design and contribute to LEEDcertification requirements

Awareness, guidance, financial

Property tax abatements or tax relief of $4.50 per ft2 (up to $100,000 or the building's tax liability, to property owners that green roofs

N/A

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Awareness, guidance, mandatory

The NYC Green Infrastructure Plan 2008 Green Roof and Solar Tax Abatement Program

Portland, OR, USA

Portland Incentives Green Building Policy density bonus, grants for (2001) Clean River Rewards retrofits, (2005) mandatory Stormwater Management Manual (1999)

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New York City, USA

San Francisco, USA

City and County of San Francisco 2030 Sewer System Master Plan San Francisco’s Property Assessed Clean Energy (PACE)

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Los Angeles, USA

Development Policy 2007, Green Roof Improvement Fund 2006, Green Roof Grant Program 2005 The City of Los Angeles Department of Public Works Green Building Program

Awareness, guidance, incentives

Eco-roof floor area N/A ratio (FAR) bonus allows developers an extra three ft2 per ft2 of green roof without additional permits. All city owned buildings are required to have 70% green roof. Additional stormwater reduction discount programs Properties with green roofs are eligible for lower rate financing programs

In 2013, 8 of 78 projects submitted for review included a green roof,

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Clean Energy (PACE) program

Incentives density bonus, public building rules

139,000 ft2 of green roof construction Awareness, guidance, incentives

Floor area ratio (FAR) bonuses determined on a case-by-case basis

The Seattle Stormwater Code

N/A

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Seattle, Washington

with a total

The Seattle Stormwater Code requires stormwater filtration and retention of runoff that can be achieved through the installation of green roofs.

City of Toronto provides Green Roof Bylaw 2009, EcoRoof Incentive Program 2009, Guidelines for Biodiverse Green Roofs 2013

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Seattle’s Green Factor Policy

Awareness, guidance, financial incentives, regulations

Seattle’s Green Factor requirements for new developments which can be achieved with green roofs and green walls From 2010, Bylaw mandates GR on all new commercial, institutional, residential developments of 2000 m2 or more gross floor area. From 2012, bylaw additionally applies to industrial developments. Eligible GR receive CAD $75/m2 up to

From 20102015, 260 GR projects measuring 19.6 Ha created, adding to a total of 444 GR in Toronto.

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$100,000 through incentive program. Comprehensive guidelines on GR benefits, design, maintenance. Greenest City: 2020 Action Plan City of Vancouver provides Rezoning Policy for Sustainable Large Developments 2014

Awareness, guidance, mandatory

All new building rezonings are required to meet LEED Gold standard

Tokyo, Japan

Tokyo Green Plan 2012; Tokyo Metropolitan Government Environmental White Paper 2006 and Nature Conservation Ordinance; Tokyo 2020; The Green Building Program 2002 and Tokyo Metropolitan Condominium Environmental Performance Labelling System; 10 Year Project for Green Tokyo 2006; Japanese national building law 2005.

Awareness, financial incentives, regulations, monitoring

All new private buildings greater than 1000 m2 and public buildings greater than 250 m2 mandated to have at least 20% greened roof or incur US$2000 fine. The Green Building Program assesses and publishes efforts made by developers to promote green architecture. Project for Green Tokyo provides tax incentives. Government leadership aiming to create 400 ha of green roofs and walls on offices, schools, hospitals, and in areas adjacent to roads, railroads and parking lots between 2006 – 2016, making use of green

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Green roofs are incorporated in LEED design and contribute to LEEDcertification requirements

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Vancouver, Canada

From 2000 to 2001, total area of green roofs in Tokyo increased from 5.24 ha to 10.44 ha. 57.2 ha of green roofs and walls installed between 2007 – 2010.

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fundraising schemes. National law requires all new apartment or office buildings in urban areas to

Awareness, guidance, financial incentives, GRGW monitoring

Abundance of intensive green roofs due to dense urban environment, lack of recreation space at ground level, market-driven desire for attractive landscaping, building and development requirements.

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Singapore, Republic of Singapore

Comprehensive guidelines on benefits, design, plant selection, installation, maintenance, and costs of intensive and extensive green roofs in Hong Kong. Government policy encourages green roofs on public buildings, JPN1 and JPN2 promote green features by exempting communal sky gardens and podium gardens from gross floor area and site coverage taxes thus providing economic benefit to the developer.

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Awareness, guidance, financial incentives, regulations, research

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Hong Kong Government Policy Address 2006-2007, 2004 Green and Innovative Buildings (JPN1) and 2006 Second Package of Incentive to Promote Green & Innovative Buildings (JPN2), Amenity Features in PNAP116, provision of public and private open space in HKPSG, Town Planning Conditions, and Lease Conditions, Design and Technical Guidelines, Hong Kong Building Environmental Assessment Method, Comprehensive Environmental Performance Assessment Scheme, Architectural Services Department Green Roof Application in Hong Kong Skyrise Greenery Incentive Scheme (SGIS) 2009, SGIS 2.0 2015, Landscaping for Urban Spaces and High-Rises (LUSH) 2009, LUSH 2.0 2014

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have at least 20% vegetated rooftop.

Numerous comprehensive publications on benefits, design, plant selection, installation, contractors, maintenance of GRGW in Singapore. SGIS

SGIS 2009 assisted GRGW retrofit to over 110 buildings. LUSH 2009 added over 40 Ha building greening. Singapore has 163 GRGW,

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768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809

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covering 72 Ha (Sept 2016).

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provides funding of up to 50% GRGW installation costs. LUSH provides development exemptions and incentives for building greening, including GRGW.

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Highlights - Green wall and green roof (GWGR) projects were identified across Australia -Presence, types, and absence of local government GWGR policies were explored -The presence of local governmental policies promoted the uptake of GWGR green infrastructure projects -Australia can improve the current policies, facilitating enhanced uptake in GWGR projects

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