Urban Sustainability-Built Environment.

Whereas a significant number of studies on building stock modeling are available, most of them have a coarse spatial resolution, thereby not providing high accuracy in material stock estimates. Also, their applications for decision-making in urban planning decisions are still limited. Using existing methods to estimate the tonnes of embodied materials and environmental impact at the urban scale is often impractical for urban planning due to cost, time constraints, or insufficient detail. We attempt to bridge this gap by developing a stock and flows model that allows the estimation of embodied building materials and their emissions, energy and water footprint for single building assessment or whole-of-city analyses. Such a model starts with the generation of level of detail 2 (LOD2) 3D building polygons derived from high-resolution LiDAR data collected in Canberra, Australia, in 2015. Building polygons were categorized into various types such as residential, commercial, and industrial. Then, each building was linked to a construction technology archetype to estimate its embodied materials. Australian-specific coefficients were used to calculate the environmental footprint of the embodied materials in Canberra’s building stock. This model was also used to estimate the material demand and environmental footprint for replacing buildings as they reach the end of their useful life and for covering the building needs of a growing population while accounting for material use efficiency trends. This model could be used as a support tool for urban planning decisions to map high-priority areas for improving the sustainability and resilience of the built environment. Model components could be substituted for more cost-effective or accurate data. For instance, for regions without LiDAR data, 3D models from aerial photography could be used. The approach can also be useful for informing strategies toward net-zero emission cities and for estimating building materials’ waste flows and the potential for the circular economy of the construction sector.