The princely and boyar yards in the Romanian Country, built in the 17th and 18th centuries represent important elements of Romanian architecture. The houses within the precincts of the yards, that is the dwellings proper, were built above an inferior level - the basement or the cellar - which form the object of the study under consideration. The evolution of the vaulting system used, as well as the manner of the planimetric-special organizing of the inferior level are two directions on which the paper is structured. Thus, if in the first half of the 17th century only the swing vaultingon transverse-rib arches were used, towards the end of the same century we can notice the appearance of intersected semicylindrical arches which later led to the type of vaulting with a central pillar and four spherical domes, used in Brancoveanu architecture and then in the first half of the 18th century. As far as the general structure of the inferior level is concerned, one notices in the same period an ever more complex arrangement, in which the main cellar becomes the nucleus around which other smaller rooms are organized. The second half of the 18th century marks adiminishing of the sizes of the houses and implicitely of the cellars, the simple cylindrical vaulting on arches being used, but on smaller openings, or arches à vela . Houses with a high inferior level were built in the same period; the separation from the dwelling level was done by means of the floors supported on wooden beams.