A novel whole-life carbon assessment of thirty buildings in California

Reducing whole-life carbon emissions from buildings is essential to achieving global climate targets. While many studies exist, few focuses on whole-life carbon assessment at the U.S. state level, such as California, which has strict decarbonization goals and a rapidly evolving policy landscape. To address this gap, we introduce a novel framework encompassing data collection, preparation, carbon calculation, whole-life assessment, and methodological variation analysis—based on data from industry professionals for thirty real buildings in California. To address inconsistency issues among data, a structured data entry template and user guide were developed and data preprocessing and alignment methods were proposed. Finally, the whole-life carbon and temporal relationship of embodied and operational carbon were quantified. Whole-life carbon intensity (WLCI) ranged from 232-2,230 kg CO 2 e/m 2 , with embodied carbon intensity (ECI) between 192-685 kg CO 2 e/m 2 and operational carbon intensity (OCI) from 13-1710kg CO 2 e/m 2 . Median values for ECI, OCI, and WLCI were 385, 228, and 734 kg CO 2 e/m 2 , respectively. This highlights that embodied carbon constituted a substantial share of total emissions, often exceeding operational carbon, which varied more due to energy sources. The analysis showed modules A1-A3, structural systems, and concrete/metals as major contributors to embodied carbon, with interiors also adding significant emissions. Methodological variations in whole-life carbon assessment were noted, particularly concerning grid decarbonization scenarios, floor area normalization, and energy data sources. Although developed for California, the methods and framework for whole-life carbon assessment are broadly applicable to global contexts. • Quantify whole-life carbon intensities based on thirty real projects in California • Propose a systematic analysis framework for building whole-life carbon assessments • Use data collection, preprocessing, and alignment to address data inconsistencies • Quantify the temporal relationship of embodied and operational carbon impacts • Address five key research questions for knowledge gaps and policy development