Which are the wastes of construction?

In the Toyota Production System, the seven wastes presented by Ohno have provided understanding on the foundations of production management and guidance for action for more than half a century. This list has been widely used also when the Toyota Production System and its derivatives, like lean production, have been adapted and diffused into other industries, such as construction. However, the seven wastes originate from a mass production context and do not cover, for example, the design stage of a productive endeavour, as it is commonly found in construction. The purpose of this paper is to contribute to the understanding of waste in construction as well as to explore the potential of creating a list of wastes particularly for this type of production. Such a list would be instrumental in creating awareness on the major waste types occurring in construction, as well as mobilizing action towards stemming, reducing and eliminating them. The discussion is structured by analyzing the sufficiency of the classical seven wastes from a construction viewpoint and by exploring alternative wastes in cases where the classical list is not found adequate. It is anticipated that this preparatory discussion will propel the next stage of research towards producing a list of wastes specifically for construction.