Commercial buildings decarbonization: Benchmarks and strategies for the United States sustainable commercial construction

• Proposes benchmarks for embodied carbon to achieve net zero by 2050 and 2100. • Aging US commercial buildings urgently need upgrades for decarbonization. • Business-as-usual scenarios deplete the carbon budget before 2050. • Hospital facilities exhibit the highest embodied carbon intensity. Achieving the United States' net-zero emissions target by 2050 necessitates a substantial reduction in both operational and embodied carbon from the building sector. This study provides a comprehensive assessment of whole-life carbon emissions of the U.S. commercial building stock- an often overlooked contributor to building-related carbon emission- by analyzing eleven building segments. Using integrated data sources, this study quantifies embodied carbon and operational carbon across multiple life cycle stages. The findings reveal that warehouses, due to their extensive floor area, contribute the largest share of embodied carbon with about 30 %, while hospitals exhibit the highest embodied carbon intensity (10.23 kg CO₂eq/m²/yr.) The aging commercial building stock, with a significant portion built before 1950, underscores the urgency for upgrades and renovations. This study used simulation and mathematical modeling techniques to define three different scenarios for the future trends of commercial buildings. The scenario analyses reveal that under current growth rates, the commercial sector could exhaust its carbon budget to limit global warming to 1.5 °C well before 2050. To address this, we propose benchmarks for embodied carbon in future constructions, emphasizing the importance of material efficiency and renovation over new construction. The study highlights the critical need for policy interventions essential for targeting embodied carbon reductions.