# An Investigation of the Selection of LEED Version 4 Credits for Sustainable Building Projects
## 6 Conclusions  
One of the major contributions of this study is bridging the gap between LEED 2009 and LEED v4 by analyzing how the new standards are functioning in practice and updating the guidance provided to project managers, enabling them to identify the most appropriate and achievable credits for their project at an early stage of the development process. To develop these recommendations, in this study we (1) identified the most commonly achieved credits and innovation for each accreditation level and (2) highlighted the differences in the credits implemented on either side of the dividing lines between LEED certification levels and (3) the association rules for the LEED credits obtained. These results provide useful information for project teams and developers seeking to identify the most appropriate LEED goals for their project, enabling them to quickly assess the most feasible credits/strategies they can utilize to help them achieve their project's objectives. In particular, these results show how useful it is to involve a LEED AP in the planning process and not just to supervise the implementation of the LEED credits related to site management once the construction phase is underway. According to the LEED v4 summary report issued by the USGBC [38], LEED v4 is more tightly focused on encouraging a performance-based approach to design. The results of the study support this, as certified-LEED v4 projects achieved higher efficiencies for both energy and water consumption. The USGBC stresses that LEED v4 is not just about updating the technical standards to take into account the latest technological innovations; it also aims to support more flexible strategies to fit the unique aspects of individual projects. However, the data collected for LEED-certified projects did reveal an imbalance between the compliance rates for the main LEED criteria. Although the impact on human health and the environment due to the choice of construction materials has led to an expanded focus on the materials criteria in LEED v4, the compliance rates for the credits belonging to these two groups of criteria (IAQ and MR) are significantly below those achieved by projects achieving certification \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline  & \multicolumn{3}{c}{**LEED 2009 (July 2015) \({}^{*}\)**} & \multicolumn{3}{c}{**LEED v4 (March 2020)**} \\ \cline{2-7}
**Main Criteria in LEED v4** & **Max Points** & **Achieved Rates** & **Ranking** & **Max Points** & **Average Points** & **Achieved Rates** & **Ranking** \\ \hline Integrative process (IP) & \multicolumn{3}{c}{Not applicable} & 1.00 & 0.60 & 59.91\% & 3 \\ Location and transportation (LT) & \multicolumn{3}{c}{Sustainable sites} & 16.00 & 7.99 & 49.92\% & 6 \\ Sustainable sites (SS) & 26 & 61.00\% & 2 & 10.00 & 4.94 & 49.37\% & 7 \\ Water efficiency (WE) & 10 & 60.80\% & 3 & 11.00 & 7.10 & 64.58\% & 2 \\ Energy and atmosphere (EA) & 35 & 40.30\% & 5 & 33.00 & 18.78 & 56.90\% & 5 \\ Material and resources (MR) & 14 & 38.70\% & 6 & 13.00 & 3.81 & 29.31\% & 9 \\ Indoor environmental quality (IEQ) & 15 & 59.10\% & 4 & 16.00 & 6.19 & 38.66\% & 8 \\ Regional priority (RP) credits & 4 & \multicolumn{3}{c}{\({}^{**}\)} & 4.00 & 3.10 & 77.59\% & 1 \\ Innovation (IN) & 6 & 67.80\% & 1 & 6.00 & 3.55 & 59.16\% & 4 \\ Total & 110 & \multicolumn{3}{c}{\({}^{**}\)} & - & 110.00 & 57.16 & - & - \\ \hline \hline \end{tabular}  
* Data from [10]. ** Data not provided in the previous studies.  
\end{table} 
Table 5: Comparison of the distribution trends for the main criteria in LEED 2009 and LEED v4. under LEED 2009. This suggests that most current project teams have not yet fully adapted to the new requirements for materials and indoor air quality credits, indicating a need for the USGBC and LEED experts to introduce additional training to support the implementation of these criteria among project teams. Local governments could also help by adopting policy measures that support green material manufacturers.