Premises for eco-efficiency analysis on construction and demolition waste recycling

Abstract

The construction industry is associated with significative impacts such a consumption of natural resources and waste generation. Eco-efficiency is an instrument for sustainable analysis which indicates the relation between environmental costs and impacts. While the most environmental method used is the lifecycle assessment (LCA), standardized by ISO 14040, the economic indicator should be selected according to the stakeholder. Total cost, Unit Cost, Net Present Value (NPV) and Internal Rate of Return (IRR) are some of the economic indicators used in the economic analysis of Construction and Demolition Waste (CDW) recycling, however, the search for literature regarding the Eco-efficiency analysis shows a tendency to use the total cost regardless of its objective. In this sense, the objective of this paper is to propose the main premises to be considered in the selection of the economic indicator and in the normalization of the analysis of the CDW recycling Eco-efficiency index results. The search method adopted was comprised for three steps: Systematic review of literature; Analysis and comparison of Eco-efficiency indicators (including economic and environmental inputs); Discussion about the main assumptions in the CDW recycling Eco-efficiency analysis. 14 articles were identified in the Science Direct and Springer platforms. This paper provides information to propose premises to the Eco-efficiency analysis on CDW recycling. As a result, was defined a standard Eco-efficiency analysis according the objective: assessment of the cost to minimizing impacts, a simple comparison between scenarios or economic and environmental viability. The first two objectives refer to the input data variation and the scenarios evaluated, respectively. The third objective needs to compare the results with the current scenario, the final disposal and established market material that recycled aggregate can replace. Using the simplified flowchart proposed for each CDW recycling Eco-efficiency analysis objective will allow to standardize studies of this aspect, thus enabling more credible, replicable and comparable development.