The research agenda for urban innovation and experimentation seems to find new momentum in recent times. The recent emergence of Urban Living Lab (ULL) is an example demonstrating such a trend. Against this background, this paper begins with the interest in clarifying what ULL is. Various sources offer many definitions of ULL, but these definitions often contain other ill-defined concepts. This paper questions the ambiguity of temporality and spatiality that is contained by ULL’s emphasis on ‘real’ time and environment. There seems also oversimplification of ULL’s origin, which potentially hinders further in-depth investigation into its non-linear and complex emergence. The reflection on the political context indicates that political drivers of ULL may be hidden behind the immediate attention to its definitions and popular perceptions. The wide range of different empirical ULL cases in the UK arguably reflects the ambiguity of its meaning. Therefore, this paper suggests re-thinking about ULL and its emergence. The attempts to summarise and simplify ULL cannot effectively clarify its complexity in nature. Well-constructed questions can take ULL as a promising opportunity to enhance and materialise long-lasting sociological enquiries.