In the frame of the project Ultimate, eight workshops were conducted by the cross-cutting technology group leaders for water recycling, material recovery and energy recovery as well as in cooperation with the “stakeholder engagement” work package. In these workshops, the concepts of the case studies were discussed at an early stage of the project together with experts from other Horizon2020 projects such as NextGen, Smart-Plant, Run4life, Sea4value, Digital-water.city, Fiware4water, Water2Return and Aquaspice. In addition, the partners from our sister projects B-WaterSmart, Water Mining, Rewaise and Wider Uptake had been invited to share their opinion with us and to identify possible synergies for cooperation.