By 2010 all educators in the English lifelong learning sector were expected to embed "education for sustainable development" to support their learners in becoming sustainable citizens. The teacher training team at a college in southwest England used a "cooperative inquiry" approach to develop themselves and their curriculum, to support their trainee teachers in achieving this. The participative nature of a cooperative inquiry made it an authentic methodology for a values-driven research project. It encouraged a sense of community within the team that extended into their practice as they engaged trainee teachers with this subject. Highlighting key aspects of the cooperative inquiry process, this paper provides an account of the team's journey, considering challenges such as time/institutional restructuring and successes, where students began to embrace education for sustainable development. Actively reflecting upon and sharing these experiences served to empower the team, leading to informed changes in their practice and behaviour. (Contains 1 note.)