NDT as a monitoring tool of the works progress and the assessment of materials and rehabilitation interventions at the Holy Aedicule of the Holy Sepulchre

•NDTs assess preservation state and pathology of the Holy Aedicule structure.•NDTs monitor the rehabilitation works of the Holy Aedicule in real time.•NDTs assess compatibility and performance of conservation and restoration materials.•NDTs support decision making during the rehabilitation works of the Holy Aedicule.•NDTs are advanced tools for monitoring rehabilitation works of complex structures. This work aims to point out the key role that Non-Destructive Techniques (NDTs) like Infra-Red Thermography, Ground Penetrating Radar, Ultrasonic Testing, Digital Microscopy, Colorimetry and Karsten Tubes, can play, not only on the diagnostic level and for the assessment of conservation interventions at the end of a project, but also during rehabilitation works. The above-mentioned NDTs, were applied for the preservation state assessment and during different stages of rehabilitation works at the Holy Aedicule of the Holy Sepulchre. Their importance for scientific support to decision making throughout diagnosis and rehabilitation works of complex historical structures is demonstrated in practice in cases such as: revealing structural layers, defect areas and voids; detecting rising damp, and thermo-hygric anisotropy of different building materials; in real time compatibility assessment of interventions as repointing, building restoration masonries, grouting, consolidating wall-paintings and protection of stone facades.