Optimizing Building Prefabrication Strategies by Balancing Modularity and Complicatedness

Offsite construction can enhance productivity, quality, and sustainability in the building industry. However, the adoption of prefabrication strategies is limited by a lack of early-phase evaluation tools, when detailed design and cost information are unavailable. This paper proposes a decision-support multi-objective framework for developing prefabrication strategies at the conceptual design stage by balancing system modularity and complicatedness. Graph modeling is used to transform the conceptual design into modular designs under hybrid panelized-volumetric strategies. Modularity is measured using a community-based index, while complicatedness is quantified by the variance of modules’ structural complexity. Trade-off Pareto-optimal prefabrication strategies are generated using evolutionary optimization. The demonstration is implemented using an Industry Foundation Classes (IFC)-based data from an actual housing project. Results show higher modularity often increases complicatedness. The finding provides critical insights to explore prefabrication strategies in the early stages of the project development to achieve an optimal balance between the project’s modularity and complicatedness.