Urban revitalization pathways toward zero carbon emissions through systems architecting of urban digital twins

Recognizing the critical role of cities in mitigating greenhouse gas emissions, many cities are adopting carbon neutrality goals as part of their climate action strategies. The efficacy of these initiatives, however, has been undermined by complexity of systemic problems, ineffectiveness in planning implementation, and lack of stakeholder engagement. Urban and community-level carbon reduction should transcend urban design and systems optimization to incorporate multi-faceted dimensions in urban contexts. To address these challenges, this paper proposes a framework of urban digital twins that includes digital representation, performance modeling, design interventions and interactive platform for decisions over temporal processes. The CANVAS, or Carbon Neutrality Architecting New Visions for Architectural Systems, is a systems architecting approach to modeling the process of urban revitalization for achieving carbon neutrality by 2050. The developed workflow integrates multidisciplinary approaches for carbon mapping, gap identification, alternative generation, Urban Building Energy Modeling (UBEM) simulation, evaluation, and decision-making to demonstrates applicability of the proposed framework through a case study of the Nihonbashi district in Tokyo. The approach revealed that Energy Use Intensity (EUI) can be decreased by 99 kWh/m²/y through reconstruction and operational improvements. Emerging photovoltaic technologies can further cut EUI by an average of 42.5 kWh/m²/y, although results vary significantly in respect to building characteristics, particularly geometry and floor area. The incremental, cyclical systems architecting approach revealed that a 97% reduction in carbon emissions could be achieved by the seventh cycle through stakeholder-centric system interventions. This paper contributes to the development of urban digital twin methodologies by integrating systems architecting concepts with UBEM as transformative tools for carbon neutral urban design and development.