Integrating life cycle assessment in space layout planning for minimizing the embodied carbon emission of modular buildings – identification of influencing factors

Space layout planning (SLP) is the process of identifying the dimensions and arrangement of physical spaces to enhance functionality and efficiency. It is considered a cornerstone of design optimization to control and improve a building’s lifecycle behaviour from different perspectives. It is, therefore, essential to understand the SLP factors that influence the building’s architectural design, particularly in residential buildings, because of the diversity and relationships between required spaces. The space layout optimization literature, however, has mostly focused on construction cost and operational energy usage as minimization functions, overlooking a comparison between design alternatives based on their lifecycle impacts. Despite the growing research in life cycle assessment (LCA) of building construction methods, there is a significant area of opportunity in the literature regarding specific SLP factors that influence the LCA of modular buildings. In response to this gap, the paper aims to identify the SLP parameters that significantly affect the LCA of modular buildings for potential SLP alternatives. To achieve this goal, the research methodology starts with a comprehensive literature analysis to identify relevant SLP parameters, focusing on architectural considerations. These parameters are further examined through a critical review of LCA literature to determine their impact on the lifecycle behaviour of modular buildings. The identified parameters are filtered based on their nature and influence on the LCA process. The key design factors influencing the LCA of various modular building layouts are validated through an expert survey method. By synthesizing findings from previous research, the study confirms the relevance and impact of selected parameters on the environmental performance of modular buildings. This approach allows designers to focus solely on the parameters they can genuinely influence—those factors that significantly impact the LCA of various layout options—while setting aside elements outside their control. By narrowing the focus in this manner, future research can better support sustainable design choices. Ultimately, the findings of this study assist designers and decision-makers in the early stages of modular building projects to concentrate their efforts on the most meaningful sustainability decisions.