The issue of workers' housing affected most big cities in the world, chiefly at the end of the XIX century. Chile was one of the pioneer countries in enacting a law system built to confront the core of the problem. The 1906 Workers' Housing Law dealt with a new situation - the growing needs of blue-collar workers regarding housing - trying to implement solutions to an ever more pressing problem, although it did not affect all of society in a similar way. In the case of Valparaiso, its particular geographical location, limited possibilities of spatial development and a context of material and social needs prevented this Law to achieve its expected results. This paper analyses the Law's impact on some of Valparaiso's territorial and urban aspects, leading to the configuration of a hybrid and exclusive urban model which has so far survived.