The supply of social housing has been marked by erosion and decline in most Western Europe countries since the 1990s, albeit with considerable variation in timing, speed and degree. Recently, it has been suggested that the sector has kept a more prominent position at the local level, at least in some cities. This paper scrutinizes this claim by comparing the development of social housing in two cities in two distinct national housing systems that have traditionally had a strong commitment to social housing: Vienna and Helsinki. To do so, we build a multi-dimensional framework that encompasses sector size, stock privatization, new housing production, and residualization. We empirically demonstrate a remarkable stability along these dimensions in both cases, albeit with some differences in degree. A number of factors need to be considered to explain this stability. They relate to aspects of institutional design of the social housing systems, as well as to continuity in policies at national and local levels.