It is commonplace to refer to the Nordic countries of Sweden, Norway, Denmark, Finland and Iceland as a distinctive and homogenous welfare regime. As far as social housing is concerned, however, the institutional heritage of the respective countries significantly frames the ways in which social housing is understood, regulated and subsidized, and, in turn, how housing regimes respond to the general challenges to the national welfare states. The paper presents a historical institutionalist approach to understanding the diversity of regime responses in the modern era characterized by increasing marketization, welfare criticism and internationalization. The aim is to provide outside readers a theoretically guided empirical insight into Scandinavian social housing policy. The paper first lines up the core of the inbuilt argument of historical institutionalism in housing policy. Secondly, it briefly introduces the distinctive ideal typical features of the five housing regimes, which reveals the first internal distinction between the universal policies of Sweden and Denmark selective policies of Iceland and Finland. The Norwegian case constitutes a transitional model from general to selective during the past quarter of a decade. The third section then concentrates on the differences between Denmark, Sweden and Norway in which social housing is, our was originally, embedded in a universal welfare policy targeting the general level of housing quality for the entire population. Differences stand out, however, between finance, ownership, regulation and governance. The historical institutional argument is, that these differences frame the way in which actors operating on the respective policy arenas can and do respond to challenges. Here, in this section we lose Norway, which de facto has come to operate in a residual manner, due to contemporary effects of the long historical heritage of home ownership. The fourth section then discusses the recent challenges of welfare criticism, internationalization and marketization to the universal models in Denmark and Sweden. Here, it is argued that the institutional differences between the Swedish model of municipal ownership and the Danish model of independent cooperative social housing associations provides different sources of resistance to the prospective dismantlement of social housing as we know it. The fifth section presents the recent Danish reform of the governance model of social housing policy in which the housing associations are conceived of as 'dialogue partners' in the local housing policy, expected to create solutions to, rather than produce problems in social housing areas. The reform testifies to the strategic ability of the Danish social housing associations to employ their historically grounded institutional relative independence of the public system.