Towards low carbon buildings: A case study in Sweden

Abstract: This study comprehensively evaluated the global warming potential of an office building in a newly built Scandinavian neighbourhood seeking to reach sustainability. The primary objective of the research was to support the city authorities of Helsingborg by providing valuable insights into actual carbon emissions at the building level and proposing measures to minimize these emissions to achieve climate neutrality by 2030. Life cycle assessment (LCA) calculations, based on the ZEB (Zero-Emission Building) complete method, were utilized to accomplish these aims. The results were then compared to those of other recently built office buildings with comparable construction specifications. Thereafter, the current gap to carbon neutrality and possible potential for improvement were estimated. The study showed that, compared to similar buildings, the case study building performs better than the average value in carbon emission. With a comprehensive calculation and quantification to assess the climate impact of the study building, the gap to carbon neutrality of this building is about 500 kg CO₂e/m² with the average European emission value for electricity, and about 400 kg CO₂e/m² with the Helsingborg municipality emission value for energy. With the extensive implementation of these measures, the most favourable scenario demonstrated remarkable proximity to the carbon neutrality objective. However, it is essential to observe that the potential for emission reduction is substantially greater when a building is designed to attain carbon neutrality. Building materials contribute significantly to carbon emissions, exceeding the impact of operational energy consumption. A rapid transition away from conventional building materials becomes essential to achieve carbon neutrality. In addition, carbon emissions can be effectively reduced by modifying building systems and materials, especially using biobased materials. However, additional research is necessary to address the complexities of accounting for biogenic carbon, end-of-life scenarios, and the potential difficulties of double counting negative carbon emissions. This study concludes with essential considerations for attaining carbon neutrality in future construction projects. The results highlight the importance of prioritizing sustainable building materials and investigating carbon capture and storage technologies, such as biogenic carbon and biochar. Ultimately, the construction industry can effectively contribute to carbon neutrality objectives by placing environmental impact alongside financial concerns. Obtaining carbon neutrality in the building industry necessitates a multifaceted strategy that incorporates energy efficiency, low-carbon materials, and sustainable urban planning while taking into account the broader environmental context.