The change of territorial organisation in the 18th century in Spain was strongly related to the preservation of the local heritage. Academic architects, military engineers, and master builders coexisted to carry out the design and management of municipal construction works. The evolution of the figure of the master builder and the confrontation with architects and the guilds since the creation of the Royal Academy of Fine Arts of San Fernando posed an inflection point in this aspect. The first aim of the present study was to highlight the figure of Vicente López Cardera, master builder in the Council and Diocese of Córdoba between the late 18th century and the early 19th century, through his work on the municipal interventions in the maintenance of the construction works and infrastructures in Montilla (Córdoba, Spain) around the year 1794. The second aim of the study was to emphasise the role of graphic engineering in the conservation of municipal heritage in the Modern Age through the study of drawings and plans provided by him in the analysed documentation. His thinking in the approach to these works fits with the ideas of social hygienic improvements that began with the Enlightenment as well as with the concept of sustainable development in culture; hence, his work is relevant in the sustainable development planning of cities in the present. With this study, missing heritage elements are also revealed, opening future lines of research that lead to their virtual reconstruction and the promotion of tourism in rural areas.