The Leadership in Energy and Environmental Design (LEED) rating system has been widely used in the US. However, until now, there has been no clear understanding of the strategies that should be used to make the transi...The Leadership in Energy and Environmental Design (LEED) rating system has been widely used in the US. However, until now, there has been no clear understanding of the strategies that should be used to make the transition from Silver to Gold certified projects. The aim of this study was to determine the trends in certified projects for both Silver and Gold LEED for New Construction and Major Renovations (LEED-NCv3) in 2016. Three performances, including (i) certification, (ii) category/subcategory/sub-subcategory certification, and (iii) cross-certification, were evaluated for both Silver and Gold LEED-NCv3 certified projects. For an ordinal measurement scale, a two-tailed Mann-Whitney U test was used. For a ratio measurement scale, an unpaired two-tailed t-test was used. If eight or more Silver and Gold certified projects occurred in the same state, then the state was selected for statistical analysis. As a result, ten states were selected. The following was revealed: (i) low certification performances for both Silver and Gold;(ii) high category performance for Sustainable Sites and Innovation in Design and low category performance for Energy and Atmosphere for both Silver and Gold projects;and (iii) three different strategies of certified projects in transition from Silver to Gold that include (a) energy-emphasized (e.g., CA), (b) non-energy-emphasized (e.g., NY), and (c) integrated (e.g., GA) strategies. We speculate that the possible reasons for such deviations in the decision strategies were due to differences between the adopted ASHRAE 90.1 standards (ASHRAE Standard 90.1 2007 or ASHRAE Standard 90.1 2010) in each of the states.展开更多
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-certifica...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.展开更多
文摘The Leadership in Energy and Environmental Design (LEED) rating system has been widely used in the US. However, until now, there has been no clear understanding of the strategies that should be used to make the transition from Silver to Gold certified projects. The aim of this study was to determine the trends in certified projects for both Silver and Gold LEED for New Construction and Major Renovations (LEED-NCv3) in 2016. Three performances, including (i) certification, (ii) category/subcategory/sub-subcategory certification, and (iii) cross-certification, were evaluated for both Silver and Gold LEED-NCv3 certified projects. For an ordinal measurement scale, a two-tailed Mann-Whitney U test was used. For a ratio measurement scale, an unpaired two-tailed t-test was used. If eight or more Silver and Gold certified projects occurred in the same state, then the state was selected for statistical analysis. As a result, ten states were selected. The following was revealed: (i) low certification performances for both Silver and Gold;(ii) high category performance for Sustainable Sites and Innovation in Design and low category performance for Energy and Atmosphere for both Silver and Gold projects;and (iii) three different strategies of certified projects in transition from Silver to Gold that include (a) energy-emphasized (e.g., CA), (b) non-energy-emphasized (e.g., NY), and (c) integrated (e.g., GA) strategies. We speculate that the possible reasons for such deviations in the decision strategies were due to differences between the adopted ASHRAE 90.1 standards (ASHRAE Standard 90.1 2007 or ASHRAE Standard 90.1 2010) in each of the states.
文摘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.
