A method for automatically making conglomerated structures (6). The method comprises a) modelling a building structure and a containing shell about the structure by a computer using a CAD software thus obtaining a file; b) extracting sections of modelled structure and of modelled containing shell, by means of horizontal planes spaced apart of a predetermined pitch, such that a plurality of section planes is generated, said planes being sorted from below towards above with respect to the model of the structure and of the model of the shell; c) depositing by a moving unit (3) on a ground a bottom-to-top plurality of layers of granular material (22) alternate to a binding material liquid sprayed on the layers at filled areas corresponding to filled portions of the of the structure and of the containing shell, according to a predetermined path; d) vertically raising the moving unit (3) according to a pitch between a deposited layer and the following layer; e) repeating the step of depositing granulating material and repeating the step of spraying the binding material on a granulated material at filled areas of the structure and of the shell as many times as the planar cross sections into which said structure and the containing shell have been divided; f) demolishing the containing shell (5) and removing unbound granular material (7) accumulated in the shell (5), thus releasing a conglomerate structure (6) that reproduces accurately said modelled structure.