The chapter focuses on the full life cycle of material and energy flows and uses in cities. Most of the impacts and opportunities in making cities more sustainable exist in how and what types of materials and energy source are used. The life cycle perspective of materials used in buildings and infrastructure systems is better addressed at the point of planning and design. The energy aspect touches both the efficiency of utilization and the impact intensity of the energy used to power and heat urban spaces and fuel transport systems. The type of sources of upstream supply of materials and energy is thus crucial. The commendable efficiency measures targeting the operation phase of urban systems should be accompanied by a consideration of the embodied impact of materials used and the end-of-life management of the materials following the end of their service life. The chapter ends with recommendations on best practices that potentially leverage on life cycle assessment results. It also covers the merits of employing the social life cycle perspective together with the environmental life cycle and economic life cycle in a life cycle sustainability assessment framework that seeks to define the triple bottom line space of lower unsustainability conditions.
Part of the book: Sustainable Cities