What are the key rationalities that underpin planning policy discourses and how do they "frame" seemingly irreconcilable conflicts around development and environmental protection? Providing an assessment of these questions, this work reviews planning policy in the UK. The authors primarily focus on their observation that the "developmental" rationality has gradually been displaced by a rationality of "sustainable development". Supported by a variety of of empirical material collected over ten years, the study examines the impact of this shift at the national, regional and local tiers of planning for housing. The overriding concern is whether planning for sustainable development can provide a satisfactory basis upon which to re-establish contemporary planning.