The dwelling is a place of shelter for the household, a unit of accommodation and a key setting for social reproduction. It can also be a place of production: household members may be involved in income generating activities, ranging from small-scale part-time tasks with few specific spatial demands, to manufacturing activities which dominate the dwelling environment. The presence of such activities within the domestic setting raises issues central to our understanding of the social nature of domestic space and how its meanings are constructed and negotiated through time. This paper will examine the conceptual and physical boundaries between income generation and domestic activities through the use of empirical data collected during residence with a family in a kampung (informal settlement) in the city of Surabaya, Indonesia. This research forms part of an international research project examining home-based enterprises in four developing world cities. Household case studies, augmented by linguistic knowledge, will be used to illustrate a range of issues including: how individuals conceptualise their working and living spheres, how boundaries are created and marked, and how changes in activity are accommodated. The analysis will demonstrate the intimate interrelationships between spaces and activities and show how domestic space is not a world apart but is continuously negotiated and re-negotiated in relation to the wider social and economic context. Such insights into the integration of non-domestic activities can inform and broaden our understanding of the production, use and meaning of domestic space.