Industrial ecology in off-site building component industry: Case study on bathroom units sectors

The paper proposes the idea of 'ecological material use' which is defined as material use where waste production and environmental impacts are reduced within the scope of product lifecycles. The paper discusses possible ecological material use of off-site building elements. It exemplifies a case study on a prefabricated three-dimensional package of a bathroom (bath-unit). Based on the interview, the paper analyzes the material use from the perspective of whole lifecycle stages of the bath-unit. It discusses the material inputs and waste outputs from manufacturing stage to dismantling stage of the bath-unit product lifecycle, then lists the factors of unrealized ecological material use of bath-unit lifecycle. Among these factors, the paper focuses on product design related issues, and on interdependencies of suppliers of elements of bathroom units. The paper lists the countermeasures to these factors. Then the paper proposes a possible idea model of ecological material use model relating to bathroom unit production and disposal by coordinating and integrating the set of strategies to these factors. In concluding comments, the paper summarizes the knowledge from the discussion on to the extent that the knowledge is applicable to other kinds of off-site building products.