A simulation-based bottom-up approach for analysing the evolution of residential buildings’ material stocks and environmental impacts – A case study of Inner Melbourne

Abstract

The building sector is material-intensive and responsible for embodied energy and greenhouse gas (GHG) emissions. Comprehensively analysing the evolution of material stocks (MSs) and associated environmental impacts in the building sector can support better decision-making on material management and energy conservation. However, there is a gap in the literature to evaluate the spatial patterns and dynamics of residential building stocks systematically and comprehensively. A simulation-based bottom-up approach is proposed to systematically analyse the spatiotemporal evolution of residential buildings’ MSs and their environmental impacts at initial and replacement stages with a high resolution. Notably, the development of the material intensity dataset is essential for analysing MSs in the building sector. The proposed innovative approach links different building characteristic factors for developing a specific material intensity dataset. The approach is demonstrated for Inner Melbourne, which has more than 260,000 residential buildings. The results illustrate the spatially and temporally explicit MSs, embodied energy and GHG emissions in the case study area. The initial spatial maps visualise that large quantities of MSs, embodied energy and GHG emissions are located in areas with clusters of houses or apartments. The replacement maps indicate the locations with large replacement material outflows where a cluster of historic buildings exist. The temporal analysis shows that the residential buildings’ MSs in Inner Melbourne have increased by a factor of 9.6 over the past 120 years, reaching 27,488 kt in 2019. The growth rate has accelerated since 1990, particularly in areas (e.g. Melbourne CBD, Docklands, Southbank and South Yarra) with a large number of apartments have been built during this period. The high resolution of the results shows the benefits of the proposed simulation-based bottom-up approach compared to the traditional approach. This result is significant as it provides new insights for evidence-based decision-making on material management and energy conservation towards a more circular construction.