Abstract: With the fabrication method and apparatus for the performance of such method, a blank containing hollow spaces extending between its lower side and its upper side is arranged in a mold closed at least at five sides and expanded. The blank is arranged in a mold box, whose area in plan view is larger than the plan view area of the blank. The space between the blank and the mold box wall and possibly hollow spaces which are retained in the blank are filled with a granular filler material, for instance sand, which is trickleable at least during the mold release of the expanded blank. In this way there is ensured for a simple and positive mold release and a protection of the mold box. The molded body can have different constructions and serve the most different purposes. The molded body is preferably constructed as a lightweight structural element for construction purposes.