Pedagogical support in early childhood education and care (ECEC) is often based on individually designed methods, although the most relevant support is the building up of organisational culture as part of the activities of all children and the whole institution. Constructing this kind of socioemotional and behavioural support practice can be linked to the creation of inclusive communities. In this paper, we analyse the actions that Finnish ECEC communities perform in their everyday life practices when they start implementing positive behaviour intervention and support (PBIS) practices. We use a year and a half pilot project as an example of the process of developing an inclusive community in ECEC. This qualitative study used inductive content analysis from longitudinal leadership team diaries (N = 18) to illustrate how the adoption of the whole-setting wide PBIS framework requires the integration of new working methods received during in-service training and the application of the practices in each of the participating ECEC communities. Results indicate that change in organisational routines is both an individual and a collective process. The three key components of development are structure, comprehension, and experimentation. The results can inform the development of inclusive institutions and practices, both in ECEC and in other educational institutions.