Increasingly, planning for housing development involves political conflict between local government planning practices, based on urban sustainability and housing intensification, and central government housing policies, centred on land supply and housing affordability. This paper examines a key historical moment in the politics of housing supply and planning in New Zealand. Drawing upon a discourse analysis of a range of housing policy documents and urban plans, this paper traces the dynamic of local and central government negotiations and conflict arising from the development of Auckland’s spatial plan, the development of the Auckland Housing Accord (a central and local government agreement to fast-track planning permission for new housing) and the implementation of the Housing Accords and Special Housing Areas Act. The paper focuses on the manner in which certain policy knowledge is prioritised and applied in the construction of affordable housing policies and how this process, which is presented as objective evidence-based policy formation, is inherently political. It is argued that the legislation supporting housing accords alters central/local government power relations and represents a challenge to the existing planning system.