Resource Recovery and Materials Flow in the City

Beyond energy efficiency, there are now urgent challenges around the supply of resources, materials, food and water. After debating energy-efficiency for the last decade, the focus has shifted to include resource and material-efficiency. In this context, urban farming has emerged as a valid urban design strategy in Europe, where food is produced and consumed locally within city boundaries, turning disused sites into productive urban landscapes and community gardens. Agricultural activities allow for effective composting of organic waste, returning nutrients to the soil and improving biodiversity in the urban environment. Urban farming will help to feed the 9 billion by 2050 (predicted population growth, UN-Habitat forecast 2009). This paper reports on best practice of urban design principles in regard to materials flow, material recovery, adaptive re-use of building elements and components (‘design for disassembly’; prefabrication of modular building components), and other relevant strategies to implement zero waste by avoiding waste creation, reducing harmful consumption and changing behaviour. The paper touches on two important issues in regard to the rapid depletion of the world's natural resources: the construction sector and the education of architects and designers.

The construction sector: Prefabricated multi-story timber buildings for inner-city living can set new benchmarks for minimizing construction wastage and for sustainable on-site assembly. Today, the construction and demolition (C&D) sector is one of the main producers of waste; it does not engage enough with waste minimization, waste avoidance and recycling. Education and research: It's still unclear how best to introduce a holistic understanding of these challenges and to better teach practical and affordable solutions to architects, urban designers, industrial designers, and so on.

One of the findings of this paper is that embedding ‘zero-waste’ requires strong industry leadership, new policies and effective education curricula, as well as raising awareness (education) and refocusing research agendas to bring about attitudinal change and the reduction of wasteful consumption.