Qualità come quantità? Considerazioni alla luce di alcune esperienze di verifica preventiva della progettazione nel campo del restauro

Preventive design verification does not have the primary purpose of checking design quality in restoration, but rather must ascertain the correspondence and congruity of the drawings for any type of project. It has, however, in the absence of the operational guidelines provided for in the Codice per i Beni culturali (2004), so far partly made up for the lack of definition of optimal criteria for restoration work, with not a few difficulties. Based on the experience conducted as a consultant specialist in restoration for agencies accredited to the validation of projects, it is possible to highlight the critical issues of this tool, the use of which is also provided for in the most recent Codice degli appalti (2023). The common interpretation of the assessment criteria is traced back to regulatory compliance and completeness of the project drawings alone. It is often suffering from misalignments of technical regulations, an inappropriate hierarchy of prescriptive values, mostly skewed toward engineering requirements, and a questionable interpretation of the same legal requirements. Validation has also been complicated by the multiplication of project deliverables and their analytical splitting, which undermine a clear synthetic and coherent restitution of operational predictions. Based on the problems encountered, some necessary corrections to the current system are suggested, to be formulated in special Guidelines aimed at ensuring the effective quality of the project. These include: the possibility of acquiring evaluation sheets from the Soprintendenze prior to the issuance of the authorization; the need to ensure a constant normative alignment of technical prescriptions; the need to ensure the organicity and consistency of general drawings at the different scale of design. Finally, we propose to use restoration performance indicators that can concisely and correctly describe the nature of the planned intervention from a conservation perspective.