An Approach to Risk Assessment and Planned Preventative Maintenance of Cultural Heritage: The Case of the Hypogeum Archaeological Site of Sigismund Street (Rimini, Italy)

This study presents a comprehensive approach to risk management and planned preventative maintenance (PPM) for cultural heritage, focusing on the hypogeum archaeological site beneath the Chamber of Commerce in Rimini, Italy. Hypogeal environments pose unique conservation challenges due to their microclimates, biological threats, and structural vulnerabilities. Applying the ABC Method—developed by ICCROM and CCI—this research systematically identifies, analyzes, and prioritizes risks associated with agents of risks. The methodology was complemented by the Nara Grid to assess the site’s authenticity and cultural value, aiding in the delineation of risk areas and informing strategic conservation priorities. The study identifies efflorescence formation, flooding risks, and lack of management guidelines as extreme threats, proposing tailored treatments and practical interventions across multiple layers of control. Through environmental monitoring, empirical analysis, and a multidisciplinary framework, the research offers a replicable model for sustainable conservation and preventive heritage management in similar subterranean contexts.