To implement learning activities in a greener way and sustain an eco-friendly approach as requested by this Erasmus+ call, the first Frontier Workshop on cutting-edge topics was hosted virtually on Teams platform by TUDelft from June 27 to July 1, 2022. The REcube Frontier Workshop is an online intensive course on cutting edge topics about pathologies and physics of reinforced concrete structures. The course introduced the selected students to the scientific advances achieved studying concrete in the context of architectural heritage, structural morphology and material with topics such as recurrent pathologies in reinforced concrete buildings, concrete chemistry, and building physics. Students attended lectures during the mornings and worked on an assignment tailored on the building of the subsequent REgenerate workshop in the afternoons. Five inhomogeneous groups were created both in terms of background and sending organization, and the same groups will be maintained in the subsequent in-person REgenerate Workshop.