Credit Mapping, Framework Restructuring, and Projected Certification-Level Migration: An Official-Text-Level Comparison of the LEED v4.1 and v5 BD+C Rating Systems

This study systematically compares the LEED v4.1 and LEED v5 Building Design and Construction (BD+C) rating systems, combining an official-text-level mapping of all 42 scored credits with an empirical score-migration projection of 49 v4.1-certified projects. LEED v5 marks a fundamental shift from a technology-oriented, credit-counting framework to a goal-driven, impact-based system organized around three core areas: decarbonization, quality of life, and ecosystem restoration. Across the BD+C family, credit entries decreased from 51 to 34 while prerequisites increased from 15 to 17, indicating greater emphasis on mandatory requirements. The most profound restructuring occurs in Materials and Resources and Indoor Environmental Quality, where embodied-carbon assessment becomes a mandatory prerequisite and occupant experience is integrated with performance verification, resilience, and equity; changes in Energy and Atmosphere are incremental by comparison. Human Impact Assessment and Climate Resilience Assessment are elevated to mandatory prerequisites, and Platinum certification imposes absolute performance targets, including full electrification and 100% renewable energy. The projection shows that 65.3% of the sampled projects would lose at least one certification level under the conservative scenario (42.9–100% across sensitivity runs), revealing a systematic score-recapture effect of the framework restructuring. These findings provide project teams, manufacturers, and policymakers with an evidence base for planning the v4.1-to-v5 transition.