This workshops aim is to  research the use of granular materials such as sand as a reusable molding material to fabricate unique building elements in concrete with a minimum of waste resulting from the formwork. The application and modeling of the sand is controlled through an industrial robot to guarantee sufficient precision and repeatability of the process. The 4 day workshop will cover basic scripting strategies in Rhino.Python and extensive tooling and prototyping using the robotic fabrication facilities at IAAC.