The intervention plan for the conservation of historical-artistic assets will include a series of activities aimed at ensuring the preservation and restoration of various artifacts. Initially, several diagnostic investigations on the materials will be planned in order to determine the nature of the layers superimposed on the original surface, with the aim of identifying the type of intervention to be carried out. 

In the specific case of Porta Angelica, there is a double chromatic layering, due to the replacement of a tower with a furnace in the 1920s, as designed in the context of the Spaccarelli-Piacentini project. The analyses will be carried out both on the materials and on the construction techniques in order to recognise and characterise the units relevant to the various construction phases, thus obtaining useful information to guide the conservative intervention on the features. Field analyses will also be carried out to characterise some parameters relating to the degree of cohesion of the material, thus obtaining objective data for the operational choices to be made for the consolidation intervention.

The restoration operations will begin with the removal of unsuitable metal elements and the preliminary cleaning of inconsistent surface deposits. The maintained metal elements will be subjected to cleaning and protective treatment before proceeding to wet cleaning of the surfaces. Subsequently, samples will be taken for chemical cleaning. Before proceeding with the consolidation phases, the surface will be thoroughly cleaned and the partially detached elements will be shored to prevent damage during subsequent operations.

For areas of greater artistic value, such as coats of arms in stone material, cleaning will be determined based on specific tests. Before grouting and styling the joints, laboratory and field tests will be carried out to identify the composition and particle size of the original mortar, maintaining consistency with previous aesthetic choices.

The plasters, after the integration of the gaps and the restoration of the adhesion to the wall support, will be veiled with pigmented lime milk, guaranteeing visual continuity with the previous restoration interventions.