Urban Metabolism (Industrial Ecology)

Principal Investigator: Dr. Kua Harn Wei

Executive summary

Industrial ecology (IE) relies upon a systems approach to consider and address the environmental impacts of human and industrial activities within the broader context of the natural systems that surround them. IE proponents advocate a shift of industrial processes from linear (open-loop) systems, in which resources move through the system and get converted into waste, to closed-loop systems where wastes become inputs for new processes. The core areas of inquiry in IE include material and energy flow studies (i.e., urban or industrial metabolism), dematerialization and decarbonization, technological change and the environment, life-cycle assessment, design for the environment ("eco-design"), extended producer responsibility and industrial symbiosis.
The study of industrial ecology within the scope and framework of high density urban planning can be understood in two ways – how urban planning can create a platform for putting IE into practice, and how IE concepts help realize sustainable high density urban forms. Cities function through the consumption, concentration and transformation of materials and energy. They can also be considered to be “urban mines” where resources, such as metals and construction waste, can be reused in new developments at the end of their useful lives. Urban metabolism studies quantify flows of resource inputs, outputs and additions to stock within selected systems.

For the purpose of this study we propose to focus on the building block as the level of analysis and will estimate the material flows and in-use stock in a specified building block system in a selected study area. We will map the built environment – residential, commercial and transportation stocks – and then quantify specific types of building materials, water and energy demanded by those structures. Based on this assessment we can determine strategies for dematerializing and decarbonizing the future built environment. We will also assess the current disposal and other end-of-life options for materials from building blocks when they are decommissioned, and will examine which of these materials could be mined for reuse in planned developments. The end result will be an assessment of total material and energy flows for city building blocks, strategies to dematerialize and decarbonize future building blocks, and an initial estimate of the feasibility of "urban mining" in this high density urban environment.

The study is an important component of the “umbrella research’ on sustainable high density living. It will complement our understanding of how high density cities can be more sustainable by looking at them from the resource use and recovery angle. Together with the other five studies, it will present a holistic perspective of how urban sustainability can be articulated in high density environments.

Objectives

The project will demonstrate scenarios of resource use and management in a high density context using industrial ecology concepts, with the view to re-look land use planning from the perspective of resource conservation and climate change concerns.

The ultimate aim is to seek ways to integrate the thinking of resource use in land use planning to minimize, conserve and recover scarce resources to achieve a more sustainable built environment.