Environmental impacts and benefits of the end-of-life of building materials – calculation rules, results and contribution to a 'cradle to cradle' life cycle

The aim of this paper is to improve the contribution of the Life Cycle Assessment (LCA) methodology to setting up a cradle to cradle (C2C) life cycle of building materials. For this, the rules included in the most recent European Standards for the environmental assessment of the waste flows in the life cycle of these materials were taken into account. The paper starts with the identification of the waste flows that can be generated or used throughout the life cycle of building materials. Standardized calculation rules for the evaluation of the environmental impacts and benefits of these flows are then described and analysed in detail. Finally, a summary of the information available in LCA databases related to the end-of-life of construction materials is presented, and selected case studies are examined to provide an overview of the contribution of the LCA approach described in European Standards to close the loop in the life cycle of building materials. This paper demonstrates that results achieved through the application of the most recent European standards on the environmental assessment of waste flows can be an important source of data for decision-making at the end-of-life of building materials, especially to ascertain whether the minimization of waste flows, the maximization of their reuse or recycling operations, or the increase of the recycled content maximizes their C2C environmental performance. This work's innovation lies mainly on the systemization, visual representation and analysis of the rules for environmental assessment of the waste flows in the life cycle of building materials, namely the ones defined in the most recent European Standards (EN 15804; FprEN 15978), and on the verification that the later can promote a C2C perspective in LCA of construction materials.