Yangyu Liu, Eleonora Brembilla, Azarakhsh Rafiee
• Developed a BIM-GIS-simulation web app for room-level daylight analysis • BIM-GIS integration supports multi-scale daylight performance assessment • Cloud-based daylight simulation enables scalable urban design analysis • Room geometry strongly influences ABDM-CBDM metric correlations • ABDM metrics serve as efficient proxies for indoor daylight performance Increasing urbanization intensifies daylight access challenges. Addressing this requires an integrated decision-making process that incorporates daylight considerations into urban design and planning. Integrated decision-making, from urban planning to building design and indoor performance, poses substantial challenges, such as data complexity, computational demand, conflicting objectives, and workflow integration. Integrating Building Information Model (BIM), Geographic Information Systems (GIS), and environmental simulation models creates an integrated decision-making platform with an intertwined design-feedback loop support. This study explores the design and development of a web application that combines script-based parametric modeling, cloud-based daylight simulation and geometry processing, and interactive geospatial visualization, allowing seamless BIM interaction to assess how dynamic changes in an urban environment affect daylight performance. This application computes façade-focused Aperture-Based Daylight Modeling (ABDM) metrics alongside traditional indoor-focused Climate-Based Daylight Modeling (CBDM) metrics. Our results demonstrate how to streamline daylight simulation to support building and urban design decision making.