: Tía Cayetana’s inn is an old road motel erected at the end of the 19th Century at Torrebaja (Spain). This inn was built using local vernacular construction techniques, i.e., with a structure made of gypsum pillars, and floors built with beams and gypsum vaulting. The facades and interior walls were built in a combination of stone masonry for the basement and either rammed earth walls or thin stone slabs wall for the upper parts. The local city hall bought the building and entrusted the rehabilitation of the building to the authors of this paper for its future use as a four-star hotel, i.e., the same use for the building more than one hundred years after its original completion. The authors of this paper made an exhaustive study of the fabrics of this building, its construction, material pathologies… and, taking into account these data, elaborated the restoration project for the building that previewed the use of the same original structure made of gypsum to be reinforced with compatible techniques. This article introduces the analysis of the local constructive technique based on the general use of gypsum for the vertical and horizontal structure, the bonding of fabrics and the external and internal coatings, and their structural performance. It also describes the reasoning that took the authors to respect the existing structure in its original condition and the reinforcements made mainly at the foundations and at the floors to assume the new weight of a four-star hotel.