The field of transdisciplinary sustainability research has brought forward a number of approaches aimed at fostering sustainability transformations and generating knowledge through collaborative experimentation in real-world settings. These cases are strongly embedded in their local context and thus the transfer of knowledge remains a key challenge. In this paper, we propose a case reporting approach that supports the structured and coherent reporting of such cases. This scheme is aimed at sustainability-oriented labs, where sustainability solutions are collaboratively developed through experimentation. The scheme focuses the reporting on local contexts, lab processes, and experiments. It is accompanied by a logic model and a set of four principles guiding the reporting procedure. The approach is designed to be general, in that it is applicable to diverse contexts and project designs, while its modularity allows the scheme to be adapted to the needs and specifics of each cases. The scheme was jointly developed and tested by a group of seven Urban Living Labs, each in their own unique context. With our approach we aim to contribute to knowledge transfer from and across cases of sustainability-oriented labs as emerging approaches in action-oriented research bridging the divide of case-based research and (meta) comparison.