The present invention relates to the automatic construction of buildings or other heavy constructions by a method and a device suitable for reducing the construction time and for assisting its relative operations. This method comprises the steps of CAD-modeling a structure through volume or surface modeling steps, sectioning the structure computed model with horizontal parallel planes according to a predetermined pitch, prearranging an apparatus that deposits in alternation a layer of granular material and a liquid binder only in coincidence with the solid portions of said plane, within containing walls that define a closed perimeter. This method can be carried out by an apparatus having a horizontal frame (1) suitable for supporting a bridge crane (15) capable of causing and operating head to move (16) in a horizontal plane defined by said horizontal frame (1). The frame (1) is movable along four uprights (3, 4, 5, 6) vertically (11,12,13,14), the bridge crane (15) is sliding horizontally (18), and the operating head is sliding horizontally (19) .