There have been numerous ‘tinkering around the edges’ attempts to improve educational outcomes for Māori, but real change will only occur when Māori are equal partners in all education decisions affecting their tamariki. This autoethnographic study analyses the effectiveness of co-design as a pathway for co-governance in Te Tātoru o Wairau, a Marlborough educational capital works project, involving iwi, the Ministry of Education, and other stakeholders. The case study critiques the project, measuring it against key indicators of Māori success: rangatiratanga (self-determination), cultural revitalisation and whānau (family) engagement. The article explores co-design’s effectiveness in achieving these goals. The most effective examples from Te Tātoru o Wairau occurred when power and resources were shared, with adequate time devoted to the co-design process alongside respect for iwi values. The findings suggest that without comprehensive sharing of power and resources, the quality of co-design is compromised, and the potential for rangatiratanga is unfulfilled. The study calls for a reinforced commitment to the principles of Te Tiriti o Waitangi across all educational levels, including school governance, to ensure successful initiatives.