TOWNSCOPE II is a computer system deleted to support solar access decision-making in a sustainable urban design perspective. The software consists of a three-dimensional urban information system coupled with solar evaluation tools. We've paid particular attention to the fact that numerical results interpretation proves to be all but trivial in complex built environments. It is nevertheless a crucial aspect in decision-making, especially for current negotiated urban design practices. Therefore it is important to develop visual instruments in order to unveil the geometrical mechanisms lying behind the final results. Various spherical projections were thereby developed, each of them presenting specific advantages and disadvantages for solar access visualisation and/or evaluation purposes. (C) 2001 Elsevier Science Ltd. All rights reserved.