Life-Cycle Assessment in the LEED-CI v4 Categories of Location and Transportation (LT) and Energy and Atmosphere (EA) in California: A Case Study of Two Strategies for LEED Projects

This study aimed to identify different certification strategies for Leadership in Energy and Environmental Design Commercial Interior version 4 (LEED-CI v4) gold-certified office projects in California’s cities and to explore these certification strategies using life-cycle assessments (LCAs). The LEED-CI v4 data were divided into two groups: high- and low-achievement groups in the Location and Transportation (LT) category. The author identified two strategies for achieving the same level of certification across LEED-CI v4 projects: (1) high achievements in LT (LT_High) and low achievements in the Energy and Atmosphere (EA) category (EA_Low), and (2) low achievements in the LT category (LT_Low) and high achievements in EA (EA_High). The author adopted LT_High–EA_Low and LT_Low–EA_High achievements as functional units for LCA. Three alternatives were LT_High: typical bus, EA_Low: gas; LT_Low: typical car, EA_High: gas; and LT_Low: eco-friendly car, EA_High: gas, where a typical bus used diesel, a typical car used natural gas, an eco-friendly car used EURO5diesel, and natural gas was used as a building’s operational energy. The ReCiPe2016 results showed that the LT_High: typical bus, EA_Low: gas strategy was preferable from a short-term perspective, and the LT_Low: eco-friendly car, EA_High: gas strategy was preferable in a long-term and an infinite time perspective, while the LT_Low: typical car, EA_High: gas strategy continued to be the most environmentally damaging certification strategy for all the time horizons of the existing pollutants. Thus, it can be concluded that if there are alternative strategies for LEED certification, an analysis of their LCAs can be useful to refine the best sustainable strategy.