A method for making a foundation in a ground, wherein: a borehole is made in the ground, the borehole having a depth; a concreting step is carried out during which the borehole is at least partially filled with concrete; a reinforcing cage is provided which comprises a framework having an upper end and extending along a longitudinal direction, the framework consisting of longitudinal steel bars extending parallel to said longitudinal direction, and of a succession of steel frames in the form of buckles fixed along the longitudinal steel bars, the framework of the cage having an upper part which is equipped with at least a coupling member having an upper end, said method being characterized in that the coupling element is disposed within a volume defined by the longitudinal steel bars and the steel buckles, the upper end of the framework of the reinforcing cage being substantially at the same level as the upper end of the coupling element and the framework of the reinforcing cage having a height smaller than the depth of the borehole; the reinforcing cage is introduced into the borehole, before or after the concreting step, such that the upper end of the framework of the reinforcing cage is below the concrete level; then the concrete is allowed to harden so as to form a concrete structure comprising a body and an upper portion extending above the body, between the upper end of the framework of the reinforcing cage and the upper end of the concrete structure; the upper portion of the body is removed from the concrete structure so as to uncover the upper end of the coupling element; and then at least one connecting reinforcement is fixed to the coupling element. a borehole is made in the ground, the borehole having a depth; a concreting step is carried out during which the borehole is at least partially filled with concrete; a reinforcing cage is provided which comprises a framework having an upper end and extending along a longitudinal direction, the framework consisting of longitudinal steel bars extending parallel to said longitudinal direction, and of a succession of steel frames in the form of buckles fixed along the longitudinal steel bars, the framework of the cage having an upper part which is equipped with at least a coupling member having an upper end, said method being characterized in that the coupling element is disposed within a volume defined by the longitudinal steel bars and the steel buckles, the upper end of the framework of the reinforcing cage being substantially at the same level as the upper end of the coupling element and the framework of the reinforcing cage having a height smaller than the depth of the borehole; the reinforcing cage is introduced into the borehole, before or after the concreting step, such that the upper end of the framework of the reinforcing cage is below the concrete level; then the concrete is allowed to harden so as to form a concrete structure comprising a body and an upper portion extending above the body, between the upper end of the framework of the reinforcing cage and the upper end of the concrete structure; the upper portion of the body is removed from the concrete structure so as to uncover the upper end of the coupling element; and then at least one connecting reinforcement is fixed to the coupling element.