Is it possible to carry out eco-sustainable rehabilitations on specially protected buildings? This is the main question and starting point for this research. We will use the tower of the Church of “Santiago Apóstol” in Montilla as a case study; with its most remote antecedents in the 15th century, it is an emblematic building of one of the most important cities in the Cordovan countryside and is listed as an Asset of Cultural Interest (Bien de Interés Cultural or BIC) as of 2001. The application of eco-efficiency criteria in the rehabilitation of this type of building might stimulate the reactivation of the construction sector in the rural area, positively impacting the promotion of a circular economy. To this end, a general methodology has been established for carrying out eco-sustainable renovations on this type of building, which defines indicators for evaluating the eco-sustainability of such interventions. This methodology is applied to the case study of this important building in Montilla to ensure that a feasible intervention has been proposed, aligned with three basic pillars of sustainability that considers its environmental, economic, and social impact.

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.