Green roofs

_61a6918Green or vegetated roofs are increasingly being built in cities to provide multiple environmental and social benefits including; reducing the quantity and improving the quality of stormwater runoff building insulation, habitat provision and improving mental health and well-being.  Although green roofs are an established technology in temperate climates in the US and Europe they are an emerging industry in Australia.  Due to differences in climate and availability of plants and growing media (substrates) technologies developed for northern hemisphere green roofs do not directly translate to Australian climates.

For the past 5 years our research group has led Australian research on plant and substrate selection to maximise the environmental and social benefits of green roofs. Our research is wide ranging and encompasses:

Plant Evaluation: We quantify the characteristics and performance of plant species for use on Australian green roofs.  This has included experiments on roofs and in controlled environments, using both Australian native and exotic plants, to identify plant traits, physiology and growth parameters that will improve green roof performance. Currently research is underway, investigating the effects of plant performance on stormwater runoff and cooling.

Developing and Testing Substrates capable of supporting plant growth which are also lightweight, chemically and physically stable, and can be retrofitted to a variety of building types. A number of our substrates based on recycled (crushed brick and roof tiles), waste materials (bottom ash) and local materials (scoria) and are now used by the green roof industry.

Quantifying the hydrology and energy benefits of green roofs. A key focus of green roofs research is investigating the interactions of substrate, soil moisture and vegetation on thermal fluxes and building insulation.

Examining the psychological and productivity benefits of green roofs for urban employees and residents and determining the most preferred green roof types.

The results of our research have been embraced by the Australian green roof industry and used to develop a number of green roofs in Melbourne including the Monash Civic Centre, Pixel Building, The Venny Community Centre and 131 Queen Street. This has culminated in the construction of   The Burnley Green Roofs which showcase different green roof plants and substrates for Australian conditions.


TITLE: Mimicking natural ecosystems to improve green roof performance
FUNDING: Australian Research Council Linkage Grant (2013-2016); Collaborating/Partner Organisation(s): Melbourne Water; City of Melbourne
RESEARCHERS: Dr Nick Williams; Prof. Tim Fletcher; Prof. Lu Aye; Dr Claire Farrell
OVERVIEW: This project will transform the Australian green roof industry by specifying plants and substrates according to ecological theory. New substrates will create markets for waste products, and diverse and resilient plant mixes will optimise nutrient and water use. Both will reduce urban energy use and stormwater runoff adapting Australian cities to climate change.

TITLE: 40-second green roof views sustain attention: The role of micro-breaks in attention restoration
FUNDING: Australian Research Council Linkage Gran; City of Melbourne, Melbourne Water, The Committee for Melbourne and the Victorian Department of Sustainability and Environment. KL was supported by a scholarship funded through the Cybec Foundation.
RESEARCHERS: Dr Kate Lee; Dr Nick Williams; Dr Kathryn Williams
OVERVIEW: This project investigated the attention benefits of viewing a green roof during a micro-break between tasks. It studied peoples responses as to whether viewing nature, and particularly green roofs, could improve concentration, mood and influences productivity.

TITLE: Green roofs – improving urban environments in a changing climate
FUNDING: Australian Research Council Linkage Grant (2010-2013); Collaborating/Partner Organisation(s): Melbourne Water; Department of Sustainability and Environment; City of Melbourne and Committee for Melbourne
RESEARCHERS: Dr Nick Williams; Assoc. Prof. Stefan Arndt; Assoc. Prof. Kathryn Williams; Dr Nigel Dunett; Dr Claire Farrell and Mr John Rayner
OVERVIEW: Green roofs are an emerging climate change adaptation technology that is widespread in Europe and North America, but rare and untested in Australia. Our research will significantly progress the Australian green roof industry by overcoming barriers to their implementation….Read more and publications


pixel monitoringTITLE: Pixel Building Green Roof
OVERVIEW: Grocon contracted us to provide advice on the construction and maintenance of the green roof on their carbon neutral Pixel office building. In order to achieve the perfect Green Building Council green star rating Grocon required a green roof that used no irrigation and reflected the original grassland vegetation of the inner Melbourne site. We developed two lightweight substrates suitable for use in the project – one scoria-based and the other a bottom-ash substrate. A small replicated experiment was undertaken to test a range of native grassland species simulating conditions on the proposed green roof. Results informed the final green roof design and planting palette which we have monitored over the past 3 years.

The Venny green roofTITLE: The Venny green roof
FUNDING: The City of Melbourne
OVERVIEW:  The Venny is a Community Centre in Kensington owned by the City of Melbourne. We were contracted to research and provide recommendations for lightweight substrates and drought tolerant plants for almost 200 square metres of green roofs to be installed on the building. This resulted in the use of three lightweight substrates and a palette of approximately 30 succulent and related plants being used across the site.


TITLE: The Growing Green Guide for Melbourne
FUNDING: Victorian Government’s Sustainability Fund under the Victorian Local Sustainability Accord and IMAP Councils
PARTNER ORGANISATIONS: The University of Melbourne and the Inner Melbourne Action Plan (IMAP) with the cities of Melbourne, Yarra, Stonnington and Port Phillip
OVERVIEW: The Growing Green Guide for Melbourne released in February 2014, has been designed to educate, inform and encourage the use of green roofs, walls and facades in Melbourne. It clarifies the potential for transformation of Melbourne’s roofs and walls into vegetated, leafy habitats and provides a guide for their construction. The GIRG undertook the writing of the technical guidelines for the guide basing it on our research The guide won the education award at the 2015 Premiers Sustainability Awards that can be downloaded for free from

Download the Growing Green Guide by clicking here.


Green Roof Fact Sheets  

Planting for survival fact sheet

Substrates for green roofs fact sheet

Planting for stormwater fact sheet

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One Response to Green roofs

  1. Mahyar says:

    Hi. It sounds interesting, I was wondering if I could know whether you have conducted any research on assessing the relationship between the green roofs and biodiversity and the role they can play.

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