With the increased demand for urban living by high-income households, sponsors of subsidised affordable housing face significant pressure and incentive to opt out of their subsidies and sell or redevelop. National evaluations of HUD data have illustrated the number and characteristics of buildings lost and the neighbourhoods in which they are located, but little has been done to better understand the specific outcomes, including the events leading up to preservation or loss of the subsidised buildings, how they were preserved or lost and what actors were engaged in the process of preservation. This study examines the ways buildings have been preserved and lost in Washington, DC, USA, to better understand the ways that local and state governments might intervene to preserve housing. I argue that affordable housing preservation is not a simple or linear process. Instead, it requires multisector monitoring, data and tools. First, there are multiple opportunities in which to intervene in the process. Second, data from all parts of the preservation puzzle are critical to the ability to intervene to prevent the loss of affordable housing. Finally, preservation is often a long and complex process that engages multiple actors at several levels, including tenants, organisers, attorneys and agency staff – and most importantly, flexible policies and funding sources.