Abstract
This article reports a first attempt to combine the analysis of socio-technical mechanisms and initiative-based learning to sense sustainability transition signals in cities. Relying on the analysis of cultural initiatives in six European Cities, the study identifies those factors that enabled social impact generation. It then formulates hypotheses about their contribution to the inception and rooting of sustainability transition dynamics. As a result, the article proposes a set of analytical categories of enabling factors acting across niches and regimes. The same factors are then reinterpreted by referring to scaling mechanisms (scaling up, out and deep). The proposed analytical scheme seeks to offer a broader reflection on the conceptual and methodological challenges related to sensing and interpreting urban sustainability transition pathways.