Casa3 is an extension to the owners' holiday home, in the Ligurian Alps, in Ormea, on the border between Liguria and Piedmont. The building is on two levels. In ancient times, it was used as a stable on the ground floor and as a barn on the first floor. The two spaces and the ratio of voids/fills of the façade opening south towards the Upper Tanaro Valley have been kept unchanged. The large window also has the function of an alcove and seat. The upper level is left free so that it can be used as a yoga room or as a covered terrace, accessible from the back of the building through a double window that can be fully opened. The style of the internal joints was made with lime-based mortar, mixed on-site with local soil to reproduce the colour of the existing stone masonry mortar. The windows and doors are made of untreated chestnut wood to allow the natural oxidation of the surfaces.