There is a widespread perception of recent deteriorating human values in Bhutan. Bhutan is promoting the concept of Gross National Happiness (GNH) in school education as one way to address this issue. Change agents' collective beliefs in their capacities to facilitate change can influence success at the institutional level. However, there is very little research on efficacy beliefs of change agents internationally and such research is nonexistent in Bhutan. This paper explores the collective efficacy beliefs at the school level, where teachers and principals work as change agents for GNH Education. (This is a part of an on-going mixed method PhD study focusing on self- and collective efficacy beliefs of principals and teachers, their perceptions of importance, support systems, and actions and impacts.) Data were gathered from principals/vice principals (N = 244) and teachers (N = 1633) of 155 schools employing tailored self-administered questionnaires with substantial parallel content. Based on the standardised collective efficacy scores, the sample schools were clustered using hierarchical cluster analysis. There were some significant differences between clusters. The paper finishes with implications for stakeholders in GNH Education.