Daylight-based solar radiation modeling for building-integrated agriculture

The increasing energy demand associated with artificial lighting in controlled and building-integrated agriculture poses a major challenge for resource-efficient food production in cities. This study presents a daylight-driven simulation framework that evaluates the extent to which available solar radiation can satisfy crop lighting requirements in urban buildings. The approach is implemented through Helianthus , a computational tool that quantifies Photosynthetically Active Radiation (PAR) and Daily Light Integral (DLI) by integrating climate data, urban geometry, material transmittance, and crop-specific light requirements. The framework introduces daylight-based solar thresholds, termed Helizones , which classify urban surfaces according to their photosynthetic-light availability and identify locations capable of satisfying crop DLI requirements through daylight alone. A multi-criteria workflow is used to assess spatial and temporal DLI distributions, crop suitability, daylight sufficiency, and supplemental lighting requirements across building and district scales. A case study conducted in high-density urban districts in Singapore demonstrates that selected crops can achieve complete fulfilment of their DLI requirements during specific periods of the year, while other cultivation scenarios substantially reduce reliance on supplemental artificial lighting. By translating urban solar radiation into biologically meaningful indicators, the proposed framework extends conventional daylight simulation beyond building-performance assessment toward crop-oriented urban agriculture planning. The results highlight the potential of daylight-responsive agricultural design to support resource-efficient food production and reduce supplemental lighting requirements in dense urban environments.