Social Innovation Laboratories, or short, social labs, represent an emerging field of lab-based inquiry to sustainability transitions, which emphasize learning through experimentation to find new ways of addressing highly complex challenges. Yet, a key challenge for these initiatives is on one hand to know whether they are “on track”, on the other hand, to evaluate their contribution to addressing a complex challenge. Our hypothesis was that adaptive capacity could serve as a lens for the evaluation of a social labs impact to building social resilience and hence in building capacities necessary for a transition towards sustainability. The aim of this research was firstly to gain a better understanding of the evaluation practices of social labs and secondly to find out how the adaptive capacity of a social lab could be evaluated and might, more generally, point towards a novel approach of evaluating in complexity for strategic sustainable development. Our results suggest that adaptive capacity could support evaluations by providing a mirror for the essential features of a social lab to be resilient. We propose three key aspects to evaluate: systems thinking, trust and prototyping capacity. Yet, this is only a first stepping stone toward an evaluation framework, which will require field testing and further research.