The purpose of this article is to explore the issues associated with the spatialization of the Institutional Resource
Regimes (IRR) approach. In particular, it discusses the IRR approach in relation with regulatory scales issues. To
this end, it first examines the concept of Functional Regulatory Space (FRS), which was developed alternatively to
IRR in order to account for policy rescaling processes. It then points out some of the limitations of the IRR and
FRS approaches with respect to explaining such rescaling processes. In order to overcome these limitations, we
then propose some theoretical developments that builds on the “politics of scale” approach. The relevance of
these theoretical developments is then discussed on the basis of a case study of a particular FRS implementation’s
failure. The Plan Rhône was established in order to solve floods issues within the meridional Rhône River basin
(South of France). However, it has never been implemented. We develop and discuss three hypotheses to interpret
this failure and demonstrate how the “politics of scale” approach usefully complements the IRR and FRS
approaches to better grasp the dynamics and complexities of policy scaling strategies.