This report summarizes the activities and findings of the 1st COACCH co-design workshop, held in Brussels in May 2018. The event included around 40 participants, with representation across the four COACCH working groups: policy makers, investors, business and industry, research and civil society. The workshop presented the COACCH co-production protocol and identified the key end-users needs of stakeholders. It discussed the in COACCH prepared report on "Knowledge Synthesis and Gap Analysis on Climate Impact Analysis, Economic Costs and Scenarios", with working sessions by sectors to identify stakeholder priorities and help inform the COACCH research agenda. Further stakeholder sessions were held on climate and socio-economic scenarios and on for stakeholder interesting tipping points, to provide additional inputs for the design of COACCH's research questions. Finally, the workshop discussed possible joint knowledge products and started the evaluation of the co-design process with a first survey.