## 2 Background  
### Heritage Structures Inspection Protocols  
Historical constructions face a unique set of challenges due to their age, architectural design, and building materials, as well as the effects of environmental changes and long-term wear. According to [13], one of the primary issues is the degradation of materials. Materials such as stone, wood, and lime mortar, commonly used in historical structures, are prone to deterioration over time. This is primarily caused by exposure to climatic factors, temperature fluctuations, humidity, and atmospheric pollutants, leading to decomposition, erosion, and corrosion. Additionally, historical buildings often experience settling and structural movement over the years, which can result from changes in soil conditions, vibrations from nearby traffic, or other external influences, causing cracks and deformations in the structure [14]. Biological attacks and biodeterioration also pose significant threats, as organisms like fungi, lichens, mosses, and insects can colonize and damage the surfaces of these structures, accelerating the deterioration of materials and affecting their overall appearance. Water-related issues are another major concern. Water infiltration through roofs, walls, and foundations can lead to severe damage, including material degradation and mold formation. Moreover, water can contribute to the erosion and corrosion of structural elements [15]. Another problem arises from the use of modern materials in repairs and restorations, which may be incompatible with the original materials of the historical buildings. This mismatch can lead to further long-term damage. Lastly, many historical constructions do not comply with modern building codes and safety regulations. Adapting these structuresto meet current safety standards and new usage requirements can be complex, often requiring careful consideration to avoid compromising their historical integrity [16]. For the inspection and conservation of historical buildings, various levels of inspection are employed to ensure the proper preservation of their cultural, architectural, and historical value [8]. These include superficial inspections conducted by conservation staff with basic evaluation knowledge but without specialized training in infrastructure pathologies. The main goal of these inspections is to identify visible damage and document it in a report. Visual inspections are carried out by technicians with some training in infrastructure inspection, without the need for special equipment, focusing on detecting visible damage from the ground to assess the general condition of the structure [17]. Main inspections involve close visual evaluations of all parts of the structure, including the ability to physically touch elements during the inspection. Deep inspections are performed during repair work and involve detailed measurements to determine the cause and extent of detected damage, providing precise information for rehabilitation planning. Special inspections are conducted in specific situations or when previous inspections raise particular concerns that require more focused investigation [18]. Several common protocols fall within these inspection levels, as described by [19; 20]. The most basic and essential method is visual inspection, which involves a direct assessment of the structure to identify visible damage, deterioration, cracks, humidity, and other surface issues such as paint detachment. Non-destructive techniques allow for the evaluation of the internal state of the structure without causing physical damage, using methods like ultrasound, thermography, electrical resistivity tomography, ground-penetrating radar (GPR), and X-rays. Material analysis involves studying the construction materials of the historical structure, often through laboratory testing, to determine their composition and characteristics, aiding in conservation efforts.