Spatial plans, or Spatial Development Frameworks (SDF), are key strategic planning tools within the territorial governance system in South Africa and a primary policy instrument for driving spatial transformation within this system. As frustration mounts with the slow pace of spatial transformation of our cities and towns, many conclude that spatial plans, and spatial planners, notwithstanding the policy commitments made in SDFs, have failed. The effectiveness of SDFs in the post-Apartheid era, and more specifically in the post-SPLUMA era of territorial governance, is evolving. There have been significant steps taken post-SPLUMA to more rigorously embed the role of the plan in governance systems and hold decision-making practices accountable to implementation of the spatial plan. Nevertheless, systemic challenges in the current territorial governance framework bring into focus the practical influence of a spatial plan in South Africa over significant levers for change in the built environment. In this context and considering that transformation of the built environment is inherently slow and incremental (Turok I, Planning for spatial transformation. In: Western Cape Government, land use planning and law reform in the Western Cape. Western Cape Government, pp 21–27, 2016), the role of SDFs in influencing decision-making is not always visible and perhaps under-estimated. This chapter explores firstly, how the effectiveness of a spatial plan or SDF should be assessed, drawing on Faludi’s (Plan Pract Res 15(4):299–318, https://doi.org/10.1080/713691907 , 2000) suggestion that a strategic plan is a tool for supporting and influencing decision-making and cannot dictate outputs and outcomes. As such its effectiveness should be assessed based on its role as a ‘learning framework’ or decision support tool. Secondly, the chapter explores contextual and structural factors that sit between and SDF and its implementation. Scrutiny of these factors is important to more accurately understand the causes of the inertia that hinder significant change, despite the best laid out plans.