The 2030 Agenda for Sustainable Development and its Sustainable Development Goals (SDGs) represent a historic global linking of health, equity and environmental sustainability. Accumulated evidence suggests that improving urban neighbourhoods to make them safer and more attractive for walking and cycling can accelerate progress towards the SDGs. The pathways to change are complex, non-linear and involve multiple pathways and multiple SDG outcomes, yet the SDG goals are often considered in isolation. Further, there have been few studies of environmental interventions for healthier transport that foreground equity. The aim of this paper is to describe and demonstrate practically how integrated interventions for placemaking and active transport can contribute to a wide range of SDG targets. First, we take an evidence-based approach to describing how such interventions are connected to targets within the SDGs. Second, we propose a complex causal theory of the pathways to change and the inter-relationships between SDGs. Third, we show, with concrete examples, how a case study project in Auckland, New Zealand illustrates these pathways, contributing to achieving the SDG targets, including barriers and challenges. We find that by addressing Goal 11 in particular ways that focus on equity (Goal 10), eight of the other goals can also be advanced. Our causal theory describes one balancing and 12 reinforcing patterns of behaviour that link interventions improvements to neighbourhoods with ten of the SDGs in a complex system. Our case study demonstrates that it is possible to successfully put this causal theory into practice through interventions, but these require strong partnerships between researchers, public health practitioners, policy-makers and communities, long-term evaluation and addressing both physical and social environments.