Rethinking the Public Space Design Process Using Extended Reality as a Game Changer for 3D Co-Design

Public space design processes are complex. Numerous preconditions and the involvement of stakeholders impede rapid decision making. Two-dimensional drawings remain the norm, although these are difficult for citizen stakeholders to understand. Public space designers rarely use 3D city models, infrastructure building information modeling, digital twins, or extended reality. Usually, 3D images (without animation) are only rendered after decision making for communication purposes. This study consists of an online questionnaire of 102 Flemish region (Belgium) stakeholders to show the appeal of and resistance to the use of 3D and extended reality in public space design processes. In a follow-up experiment, 37 participants evaluated various graphic techniques by their designs and observations. The questionnaire showed that all stakeholders lack experience with the use of virtual reality in design processes. We found that non-designer stakeholders and designers indicated that using virtual reality and interactive online 3D tools using game engines provided a better insight into communication and design. Reusing 3D designs in cycling simulators during the design process results in cost-effective quality optimization, and integration into digital twins or animated spatial time machines paves the way for hybrid, 4D cities. Extended reality supports 3D co-design that has simplicity and clarity from the outset of the design process, a trait that makes it a game changer.