Engineering firm Arup and architecture studio CLS Architetti have used a portable robot to 3D print a concrete house, which is on show for Milan design week. Printed onsite on Milan's Piazza Cesare Beccaria, the 100-square-metre house was formed over the course of a week. Made up of 35 modules, the house features curved walls, a living area, bedroom, kitchen and bathroom. The walls were was built by a robot designed by Cybe Construction, a 3D printing company from Poland, using a special mix of concrete and additives developed by Italcementi, one of the world's largest cement suppliers. The roof, windows and doors were added afterwards.