Knowledge and preservation of documentation relating to existing architecture are necessary condition for its enhancement. Firstly, through the study of archival material, it is possible to reconstruct the genesis of an architectural project. Consultation of drawings, technical reports, site photographs and other documents provides an excellent opportunity to conduct in-depth historical studies of specific architectural heritage. Bibliographic sources can help to complete the research. Secondly, because through new documentation, the result of research and studies carried out directly on the studied heritage, can initiate practices for the conservation, enhancement and renovation of existing architecture. In this sense, a digital approach facilitates the acquisition of information from the paper and simplifies the link with subsequent dissemination and/or operational stages. This article presents a research experience conducted by the Laboratorio di Studi doCme 1908 - Centro di Documentazione per Messina - of the Department of Engineering of the University of Messina and the work of the Archivio del Moderno of the Accademia di Architettura in Mendrisio (Università della Svizzera Italiana). The article analyses the themes of researching historical sources, filing, and systematizing archival documentation. Reading these two experiences in parallel made it possible to juxtapose research approaches aimed at the protection of historical material and its dissemination. It was also an opportunity to rethink a possible model for the inventory of archival documentation, suitable for the narration of the phenomenon of urban stratification and, at the same time, for the enhancement of the architectural heritage resulting from this slow phenomenon, both in the context of Messina and Ticino.