Regional governance is coming to play an increasingly pivotal role in the planning of housing development. It has been argued that an absence of formal accountability lines in regional governance is beneficial because it makes inter-municipal coordination more flexible, without the need for territorial adjustments in local authorities. However, this view is based on a narrow interpretation of public accountability. In fact, regional governance becomes effective when hierarchical accountability arrangements are structured to reinforce horizontal accountability that strengthens self-organising capacity. This paper is based on a study of regional housing planning in the province of South Holland, the Netherlands, and analyses three types of governance modes (hierarchical, horizontal and market-oriented) and public accountability relationships. The measures undertaken in the case under review to ensure effective regional housing planning under changing market circumstances highlight the need to modify accountability arrangements when policy-makers choose a new set of governance modes in order to shape relational dynamics appropriately.@en