<p>This study proposes a comprehensive approach to encourage the adoption of sustainable building delivery (SBD) practices in Somalia’s construction sector. A survey was conducted among 165 industry experts, and Partial Least Squares Structural Equation Modeling (PLS-SEM) was employed to explore relationships between key factors, while a novel hybrid Measurement of Alternatives and Ranking according to Compromise Solution–Fuzzy Synthetic Analysis (MARCOS-FSA) method was introduced to evaluate and prioritize factors influencing SBD adoption. The findings reveal that the "Use" aspect emerged as the most influential factor for SBD adoption (overall level = 7.30), followed by "Preparation" (7.17) and "Evaluation" (7.08). Specifically, effective construction management, sustainable procurement practices, government tax incentives for sustainable materials, and the dissemination of innovative construction approaches are identified as the most critical actionable priorities for decision-makers. These findings provide concrete direction for reducing building costs, enhancing local environmental quality, and promoting social cohesion in Somalia’s rapidly growing construction sector. This research makes three original contributions to the sustainable construction literature: it is among the first studies to empirically investigate SBD determinants within a fragile state context beyond the predominantly stable developing economy settings that have dominated research since Agenda 21 for Sustainable Construction in Developing Countries; it introduces the novel hybrid MARCOS-FSA decision-making method advancing beyond conventional approaches; and it generates Somalia-specific evidence demonstrating that practical utilization is the primary driver of sustainable delivery in institutionally fragile construction environments, offering a replicable framework for other fragile and rapidly developing economies beyond Somalia.</p>