Urban Heat Mitigation Tool
The Urban Heat Island Mitigation Decision Support tool (UHI-DS Tool) is a research project led by the University of New South Wales through the Cooperative Research Centre for Low Carbon Living (CRCLCL). Landcom is involved in the collaborative research as a member of the project steering committee, and has also made our projects available as test beds for the practical application of the research.
The research objectives are:
to provide governments and built environment industries with a decision-support tool to inform urban policy, development assessment and planning practices related to potential building and urban interventions, used to cool streetscapes and cities, decrease energy consumption, protect the population’s vulnerable health-wise, and improve conditions of comfort
to integrate scientific models with a range of mitigation techniques to perform urban heat island mitigation analysis across both building and urban scales, such as building coatings and roofs, urban form and density, greenery and infrastructure
to develop an Urban Heat Island Mitigation Performance Index to support governments in establishing performance targets for their planning control. The Index will indicate impact on street level temperature, health and mortality and precinct level energy consumption.16
The output from the project is critical to Landcom as it has provided a tool enabling us to model and predict the urban heat impacts in our masterplans and adapt designs to minimise the impacts. Urban heat is a key driver of climate and community resilience through its effect on energy efficiency and greenhouse gas emissions, stress on people and morbidity rates, liveability through walkability and many other facets of what makes a community sustainable.
During FY19 we completed testing the tool at Green Square Town Centre and Macarthur Heights – two very different geographic areas (inner Sydney and greater Sydney) with distinct microclimates and building types, and differing levels of natural environment surrounding the sites. The testing included site scanning with the ‘Energy Bus’ and a special drone fitted with sensors and cameras.
Results from the testing clearly show the dramatic benefits of using reflective surfaces and exposing foliage such as grass and trees. At Macarthur Heights the difference in roof surface temperature between a light grey and white roof is almost 10°C. The surface temperature of darker roofs at the hottest part of the day can be up to double the temperature of a white roof, as can be seen in the bottom images of Figure 1.
With a model that can predict the surface and air temperatures, Landcom will be able to reflect any environmental improvements realised through direct design interventions within the PRECINX models established for our projects. This means we could predict the reductions in energy usage (and GHG emissions) and cost of living improvements associated with energy use, and plan for improved walkability by knowing where the ‘cool routes’ are within a community.
The UHI-DS Tool research project came to a conclusion in FY19. Moving forward we will also review opportunities to incorporate the UHI-DS Tool in our suite of sustainable masterplanning tools.
Figure 1 Results showing temperature gradient between different surface types at Macarthur Heights.
Figure 2 Surface temperature of Green Square Town Centre, data collected by drone and stitched together to create a full map.
16 RP2023: Microclimate and Urban Heat Island Mitigation Decision-Support Tool (2018) http://www.lowcarbonlivingcrc.com.au/research/program-2-low-carbon-precincts/rp2023-microclimate-and-urban-heat-island-mitigation