Geremicca and Bilec identify a representational problem at the centre of urban metabolism: cities may be analysed as systems of flows, yet the results are still commonly communicated through static, weakly spatial formats. Their key intervention is to connect urban metabolism with digital-twin technologies capable of rendering interdependencies dynamically and geographically. The review examines seventy urban-metabolism studies and finds material-flow analysis and life-cycle assessment dominant, while maps, real-time visualisation and interoperable spatial models remain comparatively rare. A second review tracks links with Industry 4.0 technologies, GIS, LiDAR, BIM and digital twins. The conceptual operation is therefore translational: metabolic knowledge is moved from abstract accounting toward manipulable spatial environments in which planning alternatives can be tested. The paper is especially important for architecture because it makes representation part of environmental epistemology. Its bridge to wider STS and design research lies in the claim that knowledge becomes operational only when analytic systems can communicate with the representational infrastructures through which professionals actually modify cities.
URBANISM MEETS ART