The DNSH principle in Italian NRRP projects: Technical constraint or transformative lever? An integrated reading between policy, evaluation and design practices

This study analyses the application of the Do No Significant Harm (DNSH) principle in the projects of the Italian National Recovery and Resilience Plan (NRRP), considering it not only as a uniform regulatory constraint, but also as an effective process mediated by territorial, institutional, and sectoral variables. The study focuses specifically on the construction sector in Italy. Through normative and literature analysis, the research identifies the structural criticalities in the implementation of DNSH, revealing a conceptual contrast between statements of excessive formalism and the evocation of standardised parameters for assessing environmental impacts, and the key concepts of the Regional Science paradigm, such as considering territory as the primary unit of analysis and recognising the role of local institutional capacities in mediating the effectiveness of policy implementation. Four case studies in Lombardy are used to demonstrate how substantial DNSH application is possible when specific skills are supported by process management techniques, such as the Plan-Do-Check-Act (PDCA) cycle. Based on these findings, the study proposes an integrated, operational, methodological model that addresses the identified critical issues. Rather than proposing inapplicable national-scale quantitative standards, it adopts an iterative process between ex-ante evaluations and ex-post reporting.