The question of how sustainable innovations and how niche experimentation lead to systemic changes are a core motivation of sustainability transitions research. As an inherently interdisciplinary field, although this question is addressed from different academic perspectives, the dominant understanding of relevant scaling processes is grounded in concepts of growth, diffusion and expansion. This article contributes to the discussion of more nuanced understandings of scaling, acknowledging the value of ontological levels for analytic purposes, but also drawing on knowledge from socio-psychological and spatial perspectives. Alternative understandings of spatial and agency-related scaling approaches are discussed and compared. An integrative socio-spatial framework is developed, providing a mid-range framework capable of supporting analysis of transitions that connects different disciplinary perspectives within a level-based ontology.