Life cycle assessment of geotechnical works for high-rise building construction on soft clay in Sweden

Achieving climate-neutral building construction requires a comprehensive understanding of the climate impact of all relevant building elements, including geotechnical works. However, research on life cycle assessment (LCA) of geotechnical works in building construction remains limited. This study conducted a ‘cradle-to-handover’ LCA of geotechnical works for a 36-storey office building situated on soft clay in Sweden. Using project-specific data and the European Product Environmental Footprint (PEF) method v3.1 in SimaPro v9.6.0.1, the geotechnical works (modules A1–A5) contributed a climate impact of 121.1 kg CO2 equivalent (CO2eq) per square metre (m2) of gross floor area (GFA). This accounts for approximately 23.9% of the total climate impact during the construction stage, assuming the superstructure meets the proposed national-level limit value of 385 kg CO2eq/m2 GFA in Sweden. The three main contributors to the total climate impact of the geotechnical works were steel piles (64.9%), concrete piles (22.3%) and sheet pile walls (9.9%). The results highlight the need to incorporate geotechnical works into decarbonization strategies for building construction, particularly in challenging soil conditions. Furthermore, the study underscores the importance of fostering more effective communication among stakeholders to drive sustainability efforts throughout the building construction stage.