The Saint-Maurice residence in Cairo fully illustrates the reuse of Islamic architectural elements during the 19th century. Built between 1875-1879, it was dismantled in 1937. The decorative elements are certainly those of the current French Embassy in Cairo. If the multiform documentation is large, the information on the building remains incomplete. Our work toward a 3D restitution tends to demonstrate that these technologies are particularly suitable for understanding and validating multiple and fragmentary data for architectural studies. For this purpose, photographic and 3D data were acquired on-site (including ceilings and doors at the French Embassy) and compared with surveys or even old photographs and lithographs. 3D modeling based on these elements leads to a renewed visualization of the volumes, as well as the outbreak of architectural and structural inconsistencies (plans of an older state) which made it possible to refine the restitution hypotheses. The confrontation of documents with a 3D restitution has provided some answers. The acquired ceiling of the "grand salon", when placed back in the 3D model, demonstrates that the current dimensions are similar to the original ones. The other dimensions of the building are now more validated by adjustments as close as possible to all the documents. This leads to discard certain plans which appear to be architectural preliminary blueprints prior to the residence built. Enriched by hyperspectral images, this work has shown a posteriori that the origins of architectural ornaments, particularly ceramics, may be more diversified than expected. This research constitutes an essential milestone in a better understanding of the Islamic reuses of this building. However, remains to better characterize the origin of the ceramics and the appearance of the painted and sculpted decorations of the Saint-Maurice Residence in order to be able to compare it with the existing visual documents.