The purpose of this paper is to develop the concept of a housing market area, thereby provide insights into our understanding of the sub-regional structures of the housing system and hence propose a framework for strategic planning research in the housing market. To tackle this task, it is first necessary to consider the criteria for a local housing market area. The paper begins by reviewing previous definitions by both academics and planners, and their underlying assumptions. Based on the principle of spatial arbitrage, a local housing market area is defined by reference to criteria linked to migration self-containment. Parallels are drawn with the principles that have been applied to define a system of spatial labour markets using travel-to-work areas. This spatial arbitrage definition is tested empirically by developing a system of housing market areas for west central Scotland using data derived from the Land Registry, Finally, the paper draws together the empirical findings to discuss the nature of spatial housing markets and the implications for strategic planning. It argues that the establishment of a geography of functional housing market areas represents the first step in the development of systematic planning research.