This article approaches urban ethics through critically examining the production and reproduction of an eco-modern sociotechnical imaginary of sustainable urban development in Sweden, and the conditions and obstacles this poses for a just transformation. We see that notions of ecological modernization re-present problems of urban sustainability in ways that do not challenge the predominant regime, but rather uphold unjust power relations. More particularly, through an approach inspired by critical discourse analysis, we uncover what these problem representations entail, deconstructing what we find as three cornerstones of an eco-modern imaginary that obstruct the emergence of a more ethically-engaged understanding of urban sustainability. The first concerns which scales and system boundaries are constructed as relevant, and how this results in some modes and places of production and consumption being constructed as more efficient—and sustainable—than others. The second cornerstone has to do with what resources and ways of using them (including mediating technologies) are foregrounded and constructed as more important in relation to sustainability than others. The third cornerstone concerns the construction of subjectivities, through which some types of people and practices are put forth as more efficient—and sustainable—than others. Utilizing a critical speculative design approach, we explore a selection of alternative problem representations, and finally discuss these in relation to the possibility of affording a more ethical urban design and planning practice.