The digital management of heritage buildings is a new disruptive technology in the design and implementation of effective preventive preservation strategies and programmes that can manage data from such buildings and the knowledge of professional experts in the area. At heritage sites, preventive conservation requires multidisciplinary knowledge of historical heritage diagnosis; therefore, professional experts' assessments are essential. This paper presents the application of an innovative fuzzy inference system that can quantify the vulnerabilities and risks that face World Heritage Sites, as well as their functional service life. This work can help stakeholders develop innovative procedures and improve mitigation strategies, such as preventive maintenance programmes and future control systems for maximising the resilience of specific heritage complexes. To validate this innovative approach, one of the most iconic heritage buildings was used as a case study: the Royal Alc acute accent azar of Seville, Spain.