Sustained resilience as a unifying property of cities and the built environment.

The built environment evolves, deteriorates and regenerates over time, yet resilience is commonly reduced to discrete event-based recovery while long-term performance is treated through sustainability. This separation obscures how resilience unfolds across lifecycles. We introduce sustained resilience as a unifying property that integrates resilience and sustainability, capturing the cumulative and adaptive capacity of the built environment and cities to maintain function, learn from disruption and evolve through successive cycles of change.