Throughout history, waves of industrial revolutions have disrupted established manufacturing methodologies. Traditional construction processes have been transformed by new means of creating objects and computing information. The manufacturing of steel is no exception to this trend. Past methods for the creation of steel included hot forming (casting, extruding and welding), cold forming (subtractive milling, bending and rolling) and cold connected assemblies (bolts and rivets). All these methods create certain constraints to the application, form and function of steel elements. Developments within fabrication technologies bring a new dimension to the possibility of creating complex geometries in steel manufacturing. This article explores the use of new technologies including additive manufacturing as well as composite joints, and highlights the integration of new robotic programming paradigms for architectural production. Typical 3D printing technologies create objects by incrementally adding layers of material in order to create a final part. Employing robotics does not only allow for fabrication on a larger architectural scale. The flexible configurations of the robotic arm, with its six degrees of freedom, allows for the additive manufacturing of elements on top of existing structures or surfaces. Within this article we create an overview of fabrication technologies for joining steel, as well as their influence on architectural design. We explore how new technologies enable the creation of new design possibilities, through the increased flexibility of robotic fabrication.