This chapter addresses the first phase of the process of rehabilitation and adaptive reuse of abandoned mountain villages, with the aim of critically evaluating methods and tools for acquiring pre-project knowledge. The fundamental requirement of any renovation project is the understanding of physical as well as historical and cultural characteristics of the built environment, in order to consciously address all the subsequent stages of the process. The typical complexity of these villages, characterized by spontaneous constructions closely linked to the site, requires operations assisted by instrumental surveys and local historiographical research. The chapter aims to structure a method of cataloging and organizing the knowledge gained about the village to enable, at the next stage, a proper understanding of the potential of the built environment and related areas to then make informed choices in its regeneration project.