The societal need for sustainability transformation is crucial in light of climate change, and the role of individual action and behavioural changes is considered critical in meeting the Paris agreement. Radical shifts in social norms are required, which could be achieved through reaching social tipping points. These tipping points could be reached earlier by focusing on ‘greening’ communities rather than individuals. Any type of social change however, needs initiation in one way or another. Knowing what makes people advocate for pro-environmental behaviour within their community or communities, could help initiate the needed sustainability transformation. A knowledge gap was found as the literature only partly covered this topic. Sports clubs in the Netherlands are popular and relevant community settings that are increasingly stimulated towards more sustainable practices, therefore this was the setting that was focused on in the study. An exploratory approach was taken to pinpointing which helping or facilitating conditions in sports clubs are experienced by individuals who make efforts in the sustainability transformation at their club. To do this, a conceptual model was created, taking a multi-level approach and combining the capability-opportunity-motivation-behaviour (COM-B) model with environmental citizenship. A total of 17 participants who considered themselves an initiative taker or achiever for sustainability at their sports club were consulted through semi-structured interviews. Elements of grounded theory were used to shape the analysis of the acquired data. The interview transcripts were coded and analysed using the COM-components of the conceptual model. The analysis shows that there is a multitude of factors that stimulate partaking in sustainability transformation at sports clubs, with community feel or communication, and (resulting) availability of skills and knowledge standing out. Limitations of the study included taking a rather broad approach, advising future studies to further deepening more self-contained dimensions. Recommendations for supporting organisations, policy makers and sports club members with environmental concerns, included communicating about concerns and providing support regarding sustainability transformations, among others.