The FFG project “3D Welding: Additive Manufacturing of structural Steel Elements” should investigate the potential for 3D printed metals within the field of construction. The question is, is it possible to produce a building element in the correct scale which achieves the relevant static and dynamic requirements, as well as other requirements such as the surface quality and accuracy? Both topology optimised free-forms and regular forms should be investigated. Which mechanical properties can be achieved by layering weld over each other and are these constant throughout the printing process? Does the system have to be optimised so as to prevent voids and defects? Can the process be transferred from a laboratory to a building site? Is it possible to control the thickness of the layers and building elements? Which production speed is possible and can the costs be kept within a realistic budget?