Abstract

The physical learning environment shapes students' well-being, health, and learning, yet its assessment remains fragmented. Existing tools focus on isolated dimensions, particularly indoor environmental quality, and rarely document transparently how design factors are weighted or how performance thresholds are derived. This study develops the Integrated Classroom Index (ICI), an original multi-criteria index integrating three design principles: personalization, environmental comfort, and stimulus. Following a sequential mixed-methods design, a literature review defined 12 design parameters and 39 indicators, whose content was validated by 42 interdisciplinary experts through a Kappa concordance analysis. A specialized subgroup of 18 experts then assigned the weights using the Analytic Hierarchy Process (AHP). Each principle is standardized to a 0 to 1 range and combined through local and principle weights, classifying classrooms as excellent, adequate, sufficient, insufficient, or poor, with guardrails that prevent trade-offs between critical dimensions. The retained parameters reached Good to Perfect agreement (Kappa up to 1.00), the AHP was fully consistent (consistency ratio = 0.083), and the principle weights were 0.59 for personalization, 0.32 for environmental comfort, and 0.09 for stimulus. The ICI offers a transparent, reproducible, and auditable framework for evaluating and improving classroom design quality.