The real estate sector is pivotal to the sustainability transition, yet current tools struggle to consistently assess building-level Environmental, Social, Governance (ESG) performance. Green building rating systems offer robust environmental and social metrics but differ in indicator design and prioritization, limiting cross-system comparability. Portfolio-oriented platforms capture governance more effectively but lack property-level resolution. We address this challenge by developing a harmonization methodology that consolidates diverse assessment approaches into a unified framework. Through a systematic combination of leading certification systems, we construct a building-level ESG taxonomy organized into three pillars, five categories, and 18 subcategories. We apply a hybrid Analytical Hierarchy Process (AHP)-Entropy weighting method to derive standardized priority weights. The AHP component extracts subjectivity embedded in existing systems, while Entropy weighting introduces data-driven objectivity based on indicator variability. The methodology reveals governance mechanisms, driven by data coverage and stakeholder engagement, as the highest weighted dimension (40%), followed by environmental (31%) and social factors (29%). This contrasts with strong conventional emphasis on energy and emissions, but reassures recent emphasis on stakeholder engagement and processual transparency. The framework enables direct comparison of buildings assessed under different systems, supports targeted identification of efficiency improvements, and provides a quantitative basis for prioritizing sustainability interventions. By establishing standardized asset-level metrics, the framework provides the methodological foundation for transparent materiality-oriented reporting that links building performance to broader organizational sustainability disclosures. Both the taxonomy structure and weighting approach are transparent, reproducible, and adaptable to evolving assessment requirements. • Hybrid AHP-Entropy harmonizes green building certificates into ESG framework. • Entropy offsets subjectivity in AHP by deriving weights from data variability. • The harmonized weights suggest Governance (40%), Environmental (31%), Social (29%). • The framework enables consistent ESG comparison of properties through generalization. • The framework supports real estate investment and planning decision-making.
Kaufmann et al. (Fri,) studied this question.