resources, and the cost can vary due to different settings of material transports and processing. This study explores two critical questions: How does the urban density affect overall system performance? At what spatial scale could the optimal system performance be achieved? The study investigates these questions through test cases in real urban settings in Atlanta, Georgia, USA. Four neighborhoods are selected with different building densities representing the urban core, urban, suburban and rural areas, with scales of 0.5, 1, and 2 km radiuses as the system boundaries.