Lifecycle Assessment of Sustainable Construction Materials in Green Buildings: A Multi-Objective Optimization Model

Abstract

The construction sector remains one of the largest contributors to global energy consumption and greenhouse gas emissions, precipitating an urgent shift toward sustainable development practices. Green buildings aim to mitigate these environmental impacts through the adoption of eco-friendly materials and energy-efficient designs. However, the selection of sustainable materials often presents a complex decision-making problem characterized by conflicting criteria, primarily the trade-off between initial construction costs and long-term environmental benefits. This paper presents a comprehensive framework that integrates Lifecycle Assessment with a Multi-Objective Optimization model to assist decision-makers in selecting optimal construction materials. By utilizing a non-dominated sorting genetic algorithm, the study simultaneously minimizes lifecycle cost and lifecycle environmental impact, specifically embodied carbon and operational energy. The proposed model is applied to a mid-rise commercial building case study, evaluating a wide range of material alternatives for structural and envelope systems. The results demonstrate that while sustainable materials may incur a higher upfront cost, optimization can identify Pareto-optimal solutions that significantly reduce environmental footprints with marginal economic premiums. This research contributes to the body of knowledge by providing a quantitative tool that bridges the gap between economic constraints and environmental stewardship in the built environment.