This article contributes to the understanding of institutional change in urban governance through an analysis of ongoing conflicts over the regulation of development in Japanese cities. A typology of institutional change processes helps to show that while change at central and local government scales have been transformative of the institutional frameworks of land planning and land development, they are deeply contradictory in their trajectories of change. The main findings are first that urban environmental governance is subject to uneven playing fields that privilege deregulation and the neoliberalization of urban governance. It appears significantly harder to achieve stronger environmental governance capacity that requires large‐scale political mobilization, available policy frameworks and political opportunity, whereas deregulation appears to need little more than political will at the centre and an opportunistic approach to the rewriting or reinterpretation of regulations. Second, at the local scale the environmental and political incentives to create stronger planning regulations appear strong enough to support continued incremental strengthening of the planning system. In the Japanese case, at least, these two conflicting policy trajectories create a degree of contingency and open‐endedness that suggests that it is too soon to predict that the possibility of democratic and effective environmental governance is necessarily lost in the tides of neoliberalization.