A Many-Objective Optimization Model for the End-of-Life of Buildings

Abstract

The management of the end-of-life of buildings is an important concern for environmental impacts of construction and a complex topic for companies in the sector. The decision alternatives for on-site works and waste management are diverse, as are their effects on economic, work duration and environmental performances. The dependence with the case also complicates to generalize the practices. To support the companies in charge of demolition/deconstruction or renovation, a many-objective optimization model is proposed. The model considers 6 objectives: cost, delay, landfill rate, damages on resources, ecosystem quality and human health; the three last objectives are based on Life Cycle Assessment (LCA). Different constraints allow to ensure the operationality of the solutions. In order to allow a quick and easy instantiation of the model to any new demolition project, the model considers three types of data: the decision variables that will be optimized, the professional data that are valid on different study cases, and the study case parameters that are specific to the considered project. The optimization process is done via the DBEA genetic algorithm. The model was applied to a real study case and allows to build a set of pareto-optimal solutions. To assess the relevance of these solutions, an expert studied them and validated their interest and their feasibility. The diversity of solutions offered by the model is an advantage for the experts, as it offers new visions and the opportunity to explore new strategies.

Keywords: Demolition waste management, Deconstruction, multi-objective optimization, Life cycle assessment, Building end-of-life