The housing sector in Sweden, as elsewhere, faces major transitions to meet far-reaching sustainability targets. Eco-efficiency has tended to dominate the sustainability discourse, with a reliance on incremental improvements. This paper explores what is needed to reach a system-level framing of sustainability transformations in housing and home-related structures and practices. Based on previous research and empirical insights from workshops with diverse actors in the Swedish housing sector, we explore different narratives of what needs to change and perspectives on agency and collective action. Shifting the narrative from efficiency to sufficiency, and from a focus on technology and behaviour to complex interactions between actors and systems, offers opportunities as well as tensions in the sector. While the current paradigm offers limited space for action, the emergence of perspectives, policies, and practices concerning, for example, living smaller, simpler, and sharing posits the housing sector as an arena for socio-ecological transformations.