The 21st century is a time of significant change to and in urban environments and cities. The momentous and unrelenting movement of people seeking refuge in cities other than their own; the impact of weather, pandemics, terrorism and war; the effect of technology; and the transformation of concepts such as public and private highlight the urgent need to think differently about cities in relation to inhabitation. It seems appropriate, indeed vital, to bring the expertise, techniques, and concerns of the interior designer and interior architect into the urban realm to attend to how people might inhabit the urban environment. This chapter curates a series of propositions that position the practice of interior design in the urban environment. Each proposition engages a different theoretical framework in relation to the concept of “interior” and, as a consequence, a different methodology.