Integrated digital documentation methodologies for knowledge of Medieval religious complexes: the Porziuncola church in Santa Maria degli Angeli, Assisi

The Porziuncola Church is the focal point of Saint Francis’ life and his fraternity, despite the changes it has undergone over the centuries. Built upon an abandoned Benedictine chapel, it transitioned from being a small church on a secondary road to hosting the first official seat of the Franciscan Order — the place of the saint’s death and a destination for obtaining the Indulgence. The Porziuncola has never been fundamentally altered, remaining open to the faithful and becoming one of the most important relics of Franciscan worship. The building discovered by Saint Francis was likely a single rectangular stone hall, covered by a semicircular barrel vault, with traces of which are still visible on the walls. The main interventions carried out by the saint in the reconstruction of the Porziuncola seem to have focused on enlarging the openings and rebuilding the vault, which, similarly to that of the nearby Church of San Damiano, currently presents as a pointed barrel vault. This paper aims to analyse the evolution of the Porziuncola’s roof by comparing its principal pictorial representations with buildings that are similar in architectural proportions and historical context (e.g., the Church of the SS. Annunziata in Cesi). The goal is to investigate the architectural transformations over time by correlating iconographic evidence with data acquired through integrated digital documentation technologies, using close-range photogrammetric and laser-scanning techniques, to obtain a thorough and detailed analysis of the structural and formal evolution of the church’s roof.