This paper proposes a hybrid developmental Design model for innovative research, practice and learning in complex socio-technical systems by combining topical theories and methods. It begins by challenging the problem of exclusive Design approaches and typical Design models which use centralised development and beneficiation. The model asks Designers to rethink their future role and relinquish control via a Participatory Design approach where Designers are responsible for demystifying the value impact of Design through a process of ongoing engagement (Lasky 2013, p. 24). The model’s framework combines three Design theories that have common themes: ‘Socio-Technical Systems Design’, ‘Appropriate Technology’ and ‘Design for Sustainability’.