Abstract.The complexity of today’s societal challenges calls for collaborative effort and novel approaches. Living lab is an extremely attractive open innovation landscape for collaborative research and development activities targeting societal challenges. Not surprisingly, living lab literature is saturated with evidence of how (transdisciplinary) collaboration between different scientific disciplines and sectors, and involving the end user, is vital for the living lab success. However, although there is plenty of support for collaboration, in other words – why we must collaborate, today we still lack clear guidelines to direct transdisciplinary stakeholder networks of academics and practitioners through collaboration process in the living lab ecosystem. In other words, we lack answers to the question how to collaborate. In present paper we propose a conceptual framework to guide stakeholders involved in transdisciplinary collaboration through collaboration initiation phase. We base our framework on collaboration challenges described in the literature, specifically the need for stakeholder alignment, as well as challenges experienced in practice, which we report through exploratory case studies. In proposed conceptual framework we advocate for employing of co-creation methods on a meso and macro layers of a living lab ecosystem in order to collaboratively define living lab scope and strategy and facilitate stakeholder alignment. Additionally, we integrate an iterative approach and a feedback loop in order to account for the dynamic nature of collaboration process and to enable reflection and evaluation.