There is a persistent housing crisis in England which is however paired with strong resistance to development, particularly in the greenbelt. Densification seems to be the logical answer, but according to policy think tanks with limited uptake outside city centres. Based on a three-year research project, this paper sheds light on a decade of suburban densification in England looking a detailed spatial data, policy documents and interviews with key actors. The findings of the project show the varied nature of suburban densification, showing that densification is taking place on a larger scale than postulated. It provides insights in the different types of densification looking at processes and outcomes and their respective geographies. The research then looks at the role of planners and the planning system, concluding that densification seems to be happening mostly under the radar. Planning policy for suburban areas is mostly passive, which has implications for the design quality of suburban densification.