The pairing of physical objects with a digital counterpart, referred to as a digital-physical twin, provides the capability to leverage the affordances of each. This can be applied to city scale visualisation during concept generation to engage citizens with city planning. A Virtual Reality based platform is proposed, tested with members of the public and its suitability as an engagement tool is discussed. The platform, City Blocks, allows later design stage visualisation and analysis of ideas to be brought to concept development with citizens able to reason and refine designs via an abstracted physical twin.