Co-creation is an emerging trend in construction management research and architectural transdisciplinary practice. With action research in architectural practice, a new perspective on the act of co-creating together in the design process, was explored in the architectural design phase. Co-creation through the lens of gestalt-theory brought other solutions than the traditional design process. Findings illustrate how the Gestalt-approach to co-creation in architectural practice is different in the way that the relational is in focus. Gestalt brought a systemic perspective on forces of resistance of change, which led to the creation of a new digital tool for participatory design. The Gestalt approach was also found to be supportive of bridging fragmented knowledge perspectives into a meaningful whole and integrated design. Further, it challenged the role of the architect and the power distribution when creating. The contribution to practice was twofold: 1) an innovative design solution for urban resilience; 2) the invention of a new digital tool supporting participatory design processes. In conclusion, it was found that by engaging in transdisciplinary research, and thus changing the way we do things, we allow for different ideas and solutions to emerge. However, the paper offers only one in-depth case-study, but still provide design practice and construction management research, with insights on how to co-create in the early 'fuzzy' phase of design.