… of technical waxes The goal of this research cooperation between B+S Engineering GmbH from Rheine, Germany and the Institute of Structural Design (ITE) at the TU Braunschweig, Germany, funded by AiF Projekt GmbH (project-executing organization of the Federal Ministry of Industry and Energy (BMWi) for "ZIM cooperation projects" - funding period mid-2017 to end 2018), is to examine the economic efficiency and ecological sustainability of wax moulds for free-form concrete structural elements and to develop the non-waste wax mould technology  into an application suitable for construction practice. The manufacture of free-formed concrete structural elements in a cost-effective and resource saving industrial process is to be made possible through the development of a fully automated production process. By adding together modular wax mould segments to form a complete mould, concrete structural elements can be manufactured with an almost unlimited range of shapes and in a size that is almost arbitrarily extendable. Serial unique items can be manufactured cost-effectively through the merging of individualised manufacturing technology and serial process technology. This report includes the results from the underground constructions part of the research projects, which were obtained in the first half of the funding period.