## 4 Conclusions  
LEED, as a generally accepted international building rating system, has tried to take into account the environmental priorities of countries other than the US. In this regard, a flexible weighting system of LEED points toward adaptation to the environmental problems of different countries is viewed as a necessary component in future LEED versions. The main contribution of this study is to provide feedback from the projects certified under LEED-CI v3 and v4 in two completely different countries, China and the U.S. Based on country-specific data, as in this study, LEED developers will be able to build a flexible weighting system adapted to different countries. Moreover, this study presents detailed knowledge of the awarded credits to potential owners or occupants, to allow them to be better informed about the benefits of Silver and Gold LEED buildings in these two countries.  
The main findings are:  
* From Silver to Gold, in the Chinese projects, the categories' performance increased in SS, EA, and EQ with large effect size, in WE with medium effect size, and in LT with small effect size, whereas, in the U.S. projects, the categories' performance increased in EA with large effect size, in WE with medium effect size, and in SS, LT, and EQ with small effect size.
* From LEED-CI v3 to v4, in the Chinese projects, only WE performance increased, whereas, in the U.S. projects, only EA performance increased; in both countries, the EQ category's performance decreased, and the SS/LT category's performance remained almost the same.  
It can be concluded that in both LEED-CI v3 and v4, the Chinese and U.S. projects employed different strategies for the categories' performances: China performed better than the U.S. in the SS/LT and WE categories, whereas the U.S. performed better than China in the EA and MR categories. Thus, China's owners of Gold-certified projects will receive more sustainable buildings with improvements in almost all of the LEED-CI categories compared to the owners of Silver-certified projects, whereas the U.S. owners of Gold-certified projects will receive buildings with only energy and water use improvements compared to the owners of Silver-certified projects. Moreover, China's owners of LEED-CIv4-certified projects will receive buildings with only water use improvements compared to the owners of LEED-CIv3-certified projects, whereas U.S. owners of LEED-CIv4-certified projects will receive buildings with only energy use improvements compared to the owners of LEED-CIv3-certified projects.  
This study has a limitation, namely a relatively small sample size because, to date, a relatively small number of projects are certified by the current version of LEED-CI v4. As a result, the quantity of the selected LEED v3 projects was also relatively small because of the data collection methodology. This means that a relatively small sample size of the projects certified under the current LEED-CIv4 restricted the sample size of the projects certified under the previous LEED-CIv3. In this way, the total sample size was limited.  
This research received no external funding.  
The author declares that there is no conflict of interest.