On the Aventine Minor, the oratory of Santa Silvia was home to a community of oriental monks, who, in the first half of the seventeenth century, created a typical Palestinian cemetery with a small monastery that expanded with the growing prestige of the community. The construction of the Basilica of San Saba, above the oratory, was by a group of monks, “the Benedettini di Montecassino,” who lived there in the middle of the tenth century. The substructure was only recovered in the early 1900s. The study of this architectural structure is particularly interesting because there were no complete surveys and the available documentation, as far as we know, was limited to a graphical plan and section. For this reason and due to the archeological significance, it has been selected as a national research project (PRIN 2010–2011). The research has requested detailed documentation through laser scanning and photographic-based documentation. The goal of the present work is to produce a documentation of the oratory from CAD model to the BIM construction.