This paper explores the effect of urbanisation process on domiciliary behavioural patterns in papua New Guinea. Urbanisation process in PNG has had significant effects on traditional sociocultural norms despite its low level. The rate of cultural change has of course been exacerbated by many years of missionary and colonial activities. Using ethnographic and anthropological evidence the paper first traces what has, for many years, been considered traditionally acceptable and expected domiciliary behavioural patterns. These are then examined in the context of the current urbanisation process and its attendant effects. It is then argued that any severance of the traditional domiciliary behavioural patterns are likely to cause considerable stress amongst household members and kinship groups. Finally, the paper calls for detailed studies into cultural domiciliary patterns. This will enable for the designing of appropriate dwellings in which culturally acceptable behaviours can unfold unimpeded. It is argued that the built environment is extremely important for both expressing and structuring domiciliary behaviours.