Comparing international building area classifications: a crosswalk framework for measurement standards and interoperable reporting

Building-area indicators support valuation, taxation, design documentation, cadastral records, energy assessment, and urban planning, but differences in measurement objects, boundaries, and inclusion rules limit their comparability. This study frames building-area comparability as a rule-based interoperability issue rather than a terminological one. First, it compares BOMA, RICS, TEGOVA, ISO 9836, IPMS, and selected regional systems with respect to walls, partitions, low-height spaces, balconies, voids, shared areas, units, precision, and updating. Second, it systematizes terminology by proposing land- and building-related area categories, developing a crosswalk between international and regional terms, and ranking divergence sources. Third, it identifies high-risk discrepancy points and illustrates their effects through a single-case, model-based calculation. The resulting ranking identifies where comparability breaks down and the metadata required to control these discrepancies. Fourth, it defines a knowledge structure for interoperable reporting comprising a rule-based taxonomy, standards knowledge base, and metadata schema, providing a basis for future GIS/BIM decision support. The 24–30% discrepancy range reported in prior comparative studies is treated as evidence of possible sensitivity rather than a universal conversion coefficient. Comparable reporting requires metadata on the standard, category, boundary, exclusions, local basis, data source, precision, and measurement date.