The PICSOU (Performance Indicators for Core Sustainability Objectives of Universities) framework, originally designed for temperate-climate university campuses, has demonstrated promise in sustainability assessment but lacks validation across diverse environmental contexts. This study advances PICSOU’s theoretical foundation by modularizing its structure, enabling climate-specific adaptations that enhance its universality for global scalability. Focusing on Indoor Environmental Quality (IEQ) metrics, we apply the framework to Jincheng College, a large campus in Chengdu, China, situated in a subtropical monsoon climate characterized by high humidity and seasonal temperature fluctuations. For the case study, we deployed a network of high-resolution sensors across 6 dormitories, 4 classrooms, 2 offices, and 1 outdoor control site, collecting synchronized, real-time data (at 1-min intervals) over a 15-day monitoring period. Parameters included CO2 levels, PM₂.₅ concentrations, temperature, relative humidity, and occupancy patterns, providing a comprehensive dataset for analyzing human–environment interactions without reliance on assumptions. Our findings reveal significant deviations from temperate-climate benchmarks, particularly in CO2 levels and thermal comfort, highlighting the need for climate-specific adaptations within PICSOU. By introducing modular components (e.g., localized thresholds, climate-adjusted ventilation strategies), we transform PICSOU into a scalable framework capable of addressing larger campuses and diverse climatic conditions. This work not only validates PICSOU’s cross-climate applicability but also strengthens its theoretical foundation, positioning it as a universal tool for university sustainability benchmarking.