The use of housing market areas (HMAs) has become an important element of spatial planning and regional strategies in the UK. The use of HMAs also fits well within an era of market-responsive planning. In this paper we identify deficiencies in the existing planning advice for defining them in England and Scotland. The result is that the HMAs that have been produced lack consistency and are too often constrained to administrative boundaries for policy convenience. We also review existing academic studies and their theoretical underpinning. On the basis of this analysis we propose a rethink on defining HMAs, arguing for a tiered approach developed consistently on a national basis. We then develop a comprehensive tiered geography of HMAs for the whole of England. The advantages of this approach for spatial planning, and the prospects for its application, are then outlined.