Abstract
Sharing a corridor space in a rusunawa could form patterns of adaptation and exemplify the phenomenon of territorial mastery. This research aims to understand the form of this mastery as perceived by the occupants using the Grounded Theory method. The results show a theory of territorial mastery that can be developed from the findings in the field is a new theory of territorial characteristics, based on hard and soft territory. The hard territory is territorial control that is tangible or intangible, fixed or unchanged, and firm, whose existence is clear in a space that can be seen, occupied or controlled and maintained, and recognized by other residents. On the other hand, the soft territory is territorial control that is tangible and intangible, and which allows for flexible and soft shifts because it is an expression of the family and cultural emotions of guyub, so that mastery of the soft territory occurs not only because of tolerance, but also because of the prioritization of the feeling of kinship in living under one roof, and the harmonization of guyub relationships amongst people in a community