Metabolism of materials in the construction sector in developing countries

The construction industry and related ones are considered the world’s largest industrial employer and natural resources consumer. 50% of all materials extracted from the earth are transformed into construction materials and products. When these materials enter the waste stream, they account for some 50% of all waste generated prior to recycling, recovery or final disposal. In developing countries construction waste is becoming a serious environmental problem, which causes significant impacts on the environment. Thus, the minimisation of construction wastes has become a pressing issue. An assessment has been done in Costa Rica, which shows that the availability of data on material waste was scarce, the number of empirical studies is small, and mostly from developed countries, most of the studies investigated a limited number of materials in few construction sites, comparing the results is difficult, many of the studies have focussed on design of sustainable buildings and recycling of waste, scarcely information was found related to material management, and few information on waste reduction by means of material management. Besides construction materials, labour and waste production does not uniformly receive appropriate consideration and very little detailed knowledge currently exists about the origins and distributions of construction wastes. The Industrial Metabolism has been chosen as the model that helps to understand the relationship between the system and its environment, with a focus on the extraction from and the discharge to the environment of physical flows. It is a modelling method aimed at the investigation of the industrial system, the mutual interchange of physical flows between its sub-systems, and the interchange of physical flows between the industrial system and its natural environment. The main goal of the study is to gain insights into the traditional and industrialised construction processes in order to analyse the performance of the production system and its relation with the environment. This paper presents some tools that have been prepared, in order to analyse amounts of waste, causes for its production, different factors and their significance degrees that influence the production of waste.