Retrofitting the suburban garden : morphologies and some elements of sustainability potential of two Australian residential suburbs compared

Residential gardens will continue to dominate as important elements of Australian suburbs in the timeframe available for adapting to climate change. In this paper, we analyse and compare the morphologies and sustainability potential of residential suburbs and their gardens in two case studies: Traditional-suburban and Modern-suburban in the Illawarra region of New South Wales. Spatial distributions of land-cover patterns were estimated using Geographic Information Systems (ArcGIS). The four sustainability parameters measured were: roof rain water collection; local food (vegetable) production; energy and CO2 emission savings from clothes lines; and carbon benefits of onsite tree canopy cover. Outcomes suggest that land cover such as tree canopy cover and other permeable and impermeable surfaces in garden spaces can significantly impact on sustainability. Impermeable surface cover is higher in the Modern-suburban compared to the Traditional-suburban development. Traditional-suburban is more capable of supporting environmental and ecological functions through better connectivity of green spaces and availability of onsite land areas for local food production. Modern-suburban has more capacity for roof rainwater collection due to larger building roof sizes, provided there is planning for sufficient tank spaces in the design phases. These results identify specific characteristics of two suburban forms which could make positive contributions to suburban sustainability. However, changes in behaviour would be essential to utilise these capabilities of suburban environments.