Abstract: This research paper is concerned with the process of urban expansion as experienced in Perth, Western Australia between 1970 and 2005. Through an examination of urban and urban deferred rezonings to the Metropolitan Region Scheme, the focus is upon the effectiveness of two metropolitan spatial plans in shaping new urban development on the fringe of the metropolis. Drawing from growth coalitions and institutionalist theory in the construction of a theoretical backcloth for the investigation, the paper reports preliminary results which indicate that the spatial plans have been relatively impotent in determining the location and timing of urban expansion patterns – both at a metropolitan and sectoral scale. Urban development ‘breakout’ appears to have occurred consistently through the study period – pointing to actors or forces outside of the formal planning system being more influential than the spatial plans in determining outer area development outcomes.