## 1 Introduction
The IP category has one credit that aims to integrate energy- and water-efficient systems in an early design phase. The LT category contains transport-related credits, such as Access to Quality Transit, Bicycle Facilities, and Green Vehicles. The SS category includes credits with site-relevant requirements, such as Rainwater Management, Heat Island Reduction, and Light Pollution Reduction. The WE category contains Outdoor and Indoor Saving credits. The EA category intends to save energy through awarding such credits as Renewable Energy Production, Green Power and Carbon Offsets, and Optimize Energy Performance. The MR category requires life cycle consideration of products and materials with such credits as Building Life-cycle Impact Reduction, Building Product Disclosure and Optimization-Environmental Product Declarations, and Building Product Disclosure and Optimization-Material Ingredients. The EQ category deals with human health, including such credits as Low-Emitting Materials, Indoor Air Quality Assessment, and Thermal Comfort. The IN category has the possibility to award points for innovative sustainable building approaches and technologies. The RP category has bonus points, which can be received if regional environmental priorities were considered, and are awarded in six main categories: LT, SS, WE, EA, MR, and EQ. It should be noted that LEED rating systems for other types of buildings, such as LEED-CI, LEED-EB, and LEED-C&S, which (as mentioned previously) began in 2005 from the modification of LEEDv2 to different building types, also progressed through LEEDv3 to the current LEEDv4. These building type-specific LEED systems have a similar design, with some differences from the LEED-NC system credits that emphasize the relevant building type-related requirements. For example, LEED-CI in the WE category requires only indoor water saving and LEED-EB does not contain the LT category. As previously mentioned, LEED has been successfully implemented, not only in the U.S., but also in many other foreign countries [5]. For example, [PERSON] et al. [6] studied the possibility of improving the environmental quality of 14 school buildings in northern Italy according to the LEED-NCv3 system. First, the authors collected data about the actual schools' design and construction procedures that were performed at the time the buildings were constructed. Next, for each of the schools, after information about building envelopes, site conditions, local transport, water systems, and energy systems was collected, retrofit measures were suggested through application of LEED-NCv3 requirements. As a result, [PERSON] et al. [6] concluded that the schools can receive Certified/Silver certification (42-54 points were awarded as candidates for LEED-NCv3) and noted that improving school sustainability in the Italian context can be successfully done with the LEED rating system. [PERSON] et al. [7] studied the Chow Yei Ching (CYC) Building located at the University of Hong Kong, which underwent an LEED-EBv3-related energy efficient retrofit and was recognized as a Gold certified project (69 points) in 2015. In this project, all the stages of a green retrofit were performed. First, a walk-through assessment and energy survey of the existing building condition was conducted. Then, energy improvements regarding lighting, a chiller plant, windows, and a green roof were suggested. Finally, after implementation of these retrofitted improvements, energy measurement and verification were undertaken. As a result, it was concluded that energy consumption of the CYC building was reduced by 16%, demonstrating the successful implementation of LEED-EBv3 in this green retrofit process. [PERSON] et al. [8] used the LEED Operation and Management (LEED O + Mv4) system as a framework to suggest a sustainable and green retrofit for Ca' Rezzonico, a museum of 18 th century Venice (Italy).