"Comprehensive Whole Lifecycle Assessment of Buildings: Identifying Carbon Hotspots and Mitigation Strategies in Compliance with EU Taxonomy Standards"

Sustainability has become a central concern in the construction industry, as buildings play a significant role in global resource consumption and greenhouse gas emissions. Today, sustainable construction is understood not only as reducing environmental impact, but also as addressing economic efficiency and social responsibility throughout a building’s life cycle. One of the most effective methods for evaluating the environmental performance of buildings is Life Cycle Assessment (LCA). This approach assesses the impact of materials and construction processes from extraction and manufacturing to use and end-of-life. With growing awareness of climate change and resource scarcity, LCA has evolved from a research tool into a practical method for guiding design decisions. As industry moves toward lower-carbon, more resource-efficient buildings, applying LCA in the early design phases becomes essential. It enables architects and engineers to compare alternatives, optimize material use, and reduce environmental impact from the outset. This thesis explores how LCA can inform and improve sustainable building design through the analysis of different construction scenarios in a real office building project. It’s important to highlight just how big an impact construction has on the planet. This industry is one of the biggest sources of greenhouse gases and other harmful emissions. It uses more than 40% of all materials globally and is responsible for nearly 40% of all greenhouse gas emissions. Of that, 28% comes from the energy used to run existing buildings, while 11% comes from materials used in building and renovation work. The global building stock is set to double over the next 40 years, adding a staggering 230 billion square meters of new construction. This growth is akin to building a new city the size of New York every month. The expansion will be most pronounced in regions like India, which will see an increase of 45 billion m², North America with 32 billion m², and Southeast Asia with 16 billion m². This unprecedented surge highlights the critical need for sustainable building practices to curb environmental impacts and align with global climate objectives. Given the significant environmental impact of the construction sector, this thesis aims to explore how different material and design strategies can influence the carbon footprint of a building. By applying Life Cycle Assessment (LCA) to various construction scenarios, the study identifies the most effective approaches for reducing embodied carbon. The goal is to provide practical insights that support more sustainable architectural decisions and contribute to the development of lower-impact building practices. Another goal is to support a broader understanding of embodied carbon and whole-life carbon in buildings, and to help define benchmarks that the construction industry can use. This study applies a scenario-based LCA to a mid-rise office building, modelled using One Click LCA in accordance with the EN 15978 standard. Four structural and material strategies, Baseline, CAM-compliant, CLT, and Optimized, were compared to assess embodied carbon impacts. The results show that while the Baseline scenario exceeds industry benchmarks, the Optimized design achieves total embodied carbon of 525 kgCO₂e/m², successfully meeting the RIBA 2030 Climate Challenge target for non-residential buildings.