Chinese cities are the leader in building gated communities. After three-decade expansions, a recent policy is seeking to open them. We use permeability analysis to explore the ‘what if?’ question posed by the policy: what if gated communities became permeable? We asked the question in respect of non-motorised access, not for cars as the ungating policy implied. Nanchang, a medium-sized Chinese city with over 600 large gated communities, was the study area. We constructed a bespoke complete pedestrian network, for the permeability modelling. The ungated pedestrian network is 18 times longer than the gated road network. We offer the analysis to urban scholars, planners and governments by way of a quantified simulation.