This dataset supports the manuscript “Leak Safety in Low-Carbon Buildings: Standards and Detection-to-Mitigation Readiness for Refrigerants, Hydrogen, Ammonia, and Methane.” It contains the study-level evidence map and technical extraction for the final review corpus, quantitative evidence entries, standards and codes audit, standards–evidence concordance, BUILD-LEAK framework, Detection-to-Mitigation Readiness Level (DMRL) assessments, screening and retrieval records, citation-chasing audit trails, and reporting checks. The workbook is provided to support transparency and reproducibility of the review. It does not contain copies of the full-text source articles or standards.