Cognitive processes and project strategies for the conservation of historical surfaces. An application to the historical center of Catania

The urban landscape takes shape and colour with the architectural wings that combine to create the genius loci of the city with its own specificities. The perception of the urban context, however, changes with the evolution of the pathological manifestations that coexist with the stone materials constituting the building surfaces. The strategies for the enhancement of these surfaces, an integral part of the built heritage, should follow an evolving logic: it must not be concluded in definitive prescription or univocal protocols, but open to the changing process of pathogenic actions typical of, both the anthropic and natural, urban environment. The project should not be limited to timely and occasional solutions, but should aim for a more complex policy of planned conservation. With these assumptions, we are interested in an urban area made up of homogeneous architectures (both in form and materials) that are immersed in a particularly exposed environment to vehicular traffic: the Via Umberto. It was traced in the “Regulating plan for the city of Catania” (1888) as one of the axes of the modern city expansion. We proceeded to the knowledge of this city part also through a survey on the material, formal and technological characteristics of the façades, by means of a specially calibrated schedule. It also summarizes the most recurring manifestations of decay. The result of scheduling suggests reflections with clear repercussions on the intervention.