The research described in this article introduces a new, but overlooked, insights about the inverse linkages between sustainability and obsolescence. This article explores the concepts, not only at an overall level via the individual definitions of the terms, but also on social, economic, and environmental grounds that are important to sustainability discussions. Comparisons between the two notions along these three dimensions are elaborated with illustrative examples and real-life case studies. A conceptual illustration is also presented on how the two concepts operate in opposition to each other over time. This article is intended to not only introduce innovative concepts, particularly in the context of the built environment, but also to provoke healthy debate and discussion among researchers and practitioners alike. Hopefully this debate will enhance these proposed innovative concepts as well as generate new ideas and approaches toward the sustainable management of the built environment.