This research will study colonial housing politics and colonial domestic culture in the city of Semarang, Central Java, Indonesia, between 1900 and 1942, through an (1) in depth historical research with a particular attention for (visual) source material; and (2) an mobilisation of the colonial archive, in collaboration with local stakeholders. More in particular, the research seeks to investigate the extent to which cultural and moral beliefs underscored the instalment by policy makers and builders of ‘frontiers’ within the colonial territory across scales, from the urban to the interior of the house, and their negotiation by a variety of users. Through mobilizing new cartographies and acts of redrawing, of model making, of photography and film -experimental visual strategies borrowed from art and architectural practice-, these (in)visible frontiers will be unveiled. By paying attention to the intrinsic, and, at times, conflictual, relation between dominant cultural and moral values and the built environment, as well as the more ‘messy’ practices of inhabitation and use that often cross such frontiers, this research proposal fills an important gap in the current studies on Dutch colonial architecture. The specificities of the Dutch case will be highlighted through an investigation of such interior(ized) frontiers within other colonial contexts, in particular that of the former Belgian Congo.