The decreasing pace of urban development in economically-troubled Europe allows time for urban practitioners and actors to re-think planning action and its outcomes. In Canada where urban development seems unstoppable, contemplative breaks are as important. From the nibbles of recent environmental and economic crises around the world, in this article we discuss the emergence of a new theoretical approach in urban design and planning that is at the intersection of Socio-Spatial Research, Complexity Theories of Cities, and Urban Activism: Transdisciplinary Urbanism. We deploy three relevant, research projects we have been engaged with to analyze issues, challenges and limitations of Transdisciplinary Urbanism. The time frame of these interventions spans almost a decade. (C) 2015 Elsevier Ltd. All rights reserved.