In their Europan 11 Proposal, titled ‘Nudge City’, RIO Agency’s main goal was to build on a critical vision of sustainability as it is often promoted today. In their approach, the urban project cannot be a goal in itself. It has to be a frame of incentives, building on the territory’s ability to attract energies, leaning on individual aspirations to create a sustainable city. Nudges are sparks: public interventions which, designing one use, open way for a tree of possibilities. More images and architects’ description after the break.