This paper provides two discrete contributions to urban and spatial theory. The first demonstrates that within discourse analysis conceptions of time and space have analytical utility for investigations into the framings of social and urban policy. The second moves analyses of urban obsolescence beyond Marxism to demonstrate that Foucauldian theory can provide revealing insights about the stewardship of discourses of urban obsolescence through texts and visual images created by different social actors. On the basis of these two contributions I demonstrate how the Sydney metropolitan planning authority has deployed specific spatial and temporal ‘zoning technologies’ to demarcate and evaluate sections of the city. The discourses of obsolescence that have emerged in Sydney are clearly informed by market-centric ideology and discursively constructed, not in the presence of an anemic state and a rational market, but as a technology of power that is deployed by the state and serves the interests of powerful market actors. I conclude that this discursive process is leading to the demise of Sydney’s public housing estates.