Leed-NC 2009 silver to gold certified projects in the US in 2012-2017: An appropriate statistical analysis

This study aims to evaluate the Silver-to-Gold LEED-NC 2009 (Leadership in Energy and Environmental Design for New Construction and Major Renovations) cross-certification performance and categorize the cross-certification performance in eight US states in 2012-2017. The following three statistical analyses were used: (a) pooling LEED projects within a single state and single year in a single-state-year group with the subsequent use of a replication method, (b) pooling the medians of the LEED projects in each state from all years in a state-and-total-years group, and (c) pooling the LEED projects from all states and years in a total states-and-years group. The Silver-to-Gold cross-certification performance has a low propelling effect. Considering the Silver-to-Gold category cross-certification performances, the Energy and Atmosphere (EA) category has a high propelling effect, the Sustainable Sites (SS) and Environmental Quality (EQ) categories have moderate propelling effects, the Water Efficiency (WE), Materials and Resources (MR), and Innovation in Design (ID) categories have low propelling effects. Six of the eight states used an EA-high emphasized strategy, and two of the eight states used a SS/EA/WE/EQ/ID-moderate emphasized strategy. The single-state-year group and state-and-total-years group analyses are more robust than the pooling LEED projects using the total state-and-year group analysis.