Civil society actors gathered in so-called ‘community’ initiatives generate a particular impetus for low carbon transitions. This paper seeks to outline a methodological approach that can be used in order to help understand such movements, and more fundamentally, the role of community in Social Innovation (SI). The article offers an overview of Participative Action Research (PAR), and outlines its strengths and weaknesses in studying community-based social innovation, in this case the Transition movement. PAR is not an ‘off the shelf’ kit, or a ‘conforming of methodological standards’, but rather a series of approaches that ought to inform research. The paper argues that these approaches, rather than techniques, are essential to get right if the intangible, granular, and incidental-but-fundamental aspects of community are to be grasped by researchers. Given the small-scale nature of community low carbon transitions a granular analysis is preferred to a more surface, superficial overview of such processes. Qualitative research is preferred to quantitative aggregation of initiatives, due to the need to understand the everyday, more phenomenological aspects of community, and the specific tacit relations and subjectivities enacted through their capacity to cut carbon. Despite challenges with using PAR for SI, the Transition Research Network offers an active guide to achieving this.