Environmentally Sustainable Construction by Reducing Embodied Carbon Emissions in the Construction of Large-Scale Projects: a Study on High-Rise Buildings

Abstract

This research aims to comprehensively evaluate and quantify the impact of construction processes and practices in large-scale projects, focusing mainly on high-rise buildings. Employing Life Cycle Assessment (LCA) methodologies, the study measures and analyses the reduction of embodied carbon emissions throughout the construction phase. The goal is to identify and promote strategies that minimise climate change impacts associated with these projects, thereby advancing the development of environmentally sustainable high-rise buildings. The thesis addresses the urgent issue of carbon emissions in construction, explicitly examining embodied carbon from material delivery to project completion—the gate-to-use phase. Unlike extensively studied operational emissions, the effects of material selection and construction methods on embodied carbon are less understood. This research fills these gaps through rigorous investigation. Modular construction practices, such as off-site construction (OSC) and on-site techniques, can solve environmental problems and achieve sustainability in several ways; OSC or (Prefabrication) could be a successful strategy to eliminate environmental impacts caused by construction, also solving the world’s population rapid increase and housing associated issues. However, construction assessment methods like LCA must accompany multiple actions and assessment criteria. Using bibliometric analysis, case studies, and industry surveys, the research explores how strategic decisions can effectively lower the carbon footprint of high-rise buildings. It aims to enhance understanding and awareness of embodied carbon, gathering insights into current knowledge levels and identifying misconceptions. Highlighting iconic structures such as the Burj Khalifa and The Shard, the research showcases how materials such as steel and concrete, alongside advanced construction techniques, substantially reduce emissions. Surveys with construction professionals reveal a growing awareness of environmental impacts, particularly greenhouse gas emissions. However, a notable challenge persists: the need for standardised measurement units for embodied carbon, hindering comparisons across projects. To address this, the thesis proposes adopting kgCO2/m² as a standard metric to enhance clarity and comparability within the industry. The study underscores the importance of integrating sustainability from design through on-site activities. Key strategies such as prefabrication, optimised material use, and efficient waste management are critical in reducing embodied carbon. Customised sustainability approaches tailored to local climates and regulatory frameworks are also advocated. Interviews with industry stakeholders underscore a shared recognition of the need for coordinated sustainability efforts and clear guidelines for lifecycle carbon assessments. They emphasise the potential of innovative construction methods like off-site manufacturing and renewable energy integration to mitigate environmental impacts further. This research contribution to knowledge identifies practical pathways to reduce embodied carbon in high-rise construction and provides actionable recommendations for their implementation. The study advocates a holistic sustainability approach, delivering crucial insights for policymakers and industry leaders. These contributions are pivotal in advancing sustainable practices within the construction sector and fostering a greener future.