Sustainable school development is suggested to result in both meaningful learning and enhanced well-being for those involved in the reform work. The aim of the study was to gain a better understanding of the relations between the strategies utilised in school development work, school impact of the reform and burdening in the context of curriculum reform in Finland. Altogether 550 district-level stakeholders responsible for curriculum reform at the local level responded to the survey. Structural equation modelling (SEM) was utilised to explore the interrelations between the reform implementation strategy, collective proactive strategies of well-being, as well as reform-related stress and the perceived school impact of the reform. The results showed that the top-down--bottom-up implementation strategy was related to the school impact of the reform and to the use of collective proactive strategies and reduced levels of stress. Collective proactive strategies also contributed to lower stress levels and enhanced school impact. The results indicate that the top-down--bottom-up implementation strategy provides an effective way to promote sustainable school reform in terms of enhancing the collective and cumulative learning and reducing burdening of those involved in the reform.