Background <p>The complex systemic nature of Future Hospital design in the rapidly ageing city-state of Singapore calls for systems thinking. We apply this approach to answer two research questions: (i) What are the variables that drive the present and future dynamics of the Future Hospital system? (ii) How are these driving variables related?</p> Methods <p>Causal loop diagrams (CLDs) were developed collaboratively by a cross-functional system modelling team through group modelling discussions and reviews, totalling 20 sessions. Network analysis of the resulting CLDs was used to identify dominant variables.</p> Results <p>Seven interlocking CLDs (national view, cluster view, and study hospital top level, outpatient, emergency department, inpatient and surgeries and procedures views) were created to serve as “boundary objects” for different Future Hospital stakeholders, as well as researchers and planners of other Future Hospital systems. Important feedback loops and 15 interventions for redesign were identified. In all the modelled services (outpatient, emergency, inpatient and surgeries and procedures), capacities are subject to positive feedback loops. Alternative models of care are needed to restrain ever-increasing demand. Need for agility (the need for ability to quickly deploy and pivot capacity in responses to crises) is the variable with the highest betweenness centrality in the combined network of seven CLDs.</p> Conclusions <p>We address the need for greater openness on Future Hospital initiatives by making our resulting logic maps public. Due to their qualitative nature, the CLDs are insightful for Future Hospital strategic planning exercises globally.</p>