It is often assumed that traditional regulatory regimes centered on governmental action will benefit from greater private sector involvement. And, under the catchy phrase ‘from government to governance’ globally a wide variety of hybrid forms of governance has emerged. However, little empirical insight exists in the actual effects of such hybridization. The author aims at filling up this knowledge gap.He introduces a heuristic tool for comparative policy analysis, and applies this on a series of case studies. Following different building regulatory enforcement regimes in the Netherlands, Canada and Australia the author explains how different forms of private sector involvement play out in different settings. The thesis contains a wealth of scholarly and applied findings. It is insightful in showing different regime types and in suggesting meaningful differences in implementation and potential effects. The thesis adds both to studies on regulation of the built environment and its enforcement, and to studies on governance reform.