# An Investigation of the Selection of LEED Version 4 Credits for Sustainable Building Projects
## 1 Introduction  
Considerable evidence has accumulated regarding the long-term benefits of sustainable construction, especially improved energy efficiency, better financial returns, higher labor productivity, and ultimately, the reductions in global warming achieved [1, 2]. The construction industry's huge economic contribution and high energy/resource consumption in economies around the world highlight its enormous potential for significantly reducing/mitigating climate change compared with other major sectors [3, 4, 5]. [PERSON] et al. predicted that future developments in sustainable construction would reduce energy consumption by up to 50% and help limit global warming to 2 \({}^{\circ}\)C by 2050 [5]. Other studies have identified additional advantages of green buildings, such as reduced operating costs, adding 3-9% to the final value of the structure [6], and higher rental premiums of approximately 3-5% andcognitive scores [7], while those who live in them have reported sleeping an average of 46 min longer each night [8] and enjoy better indoor air quality [9]. The supporting factors that have transformed the more sustainable building industry include the green building rating systems, the most popular and well-known of which is the U.S. Green Building Council's Leadership in Energy and Environmental Design (USGBC LEED) [1,2,10]. By the end of 2019, over 146,400 projects had been registered with LEED [11]. By providing technical guides to help users balance environmental protection, energy performance, and financial benefits, LEED promotes these values in its building projects [1,2,12,13]. In addition, green building projects often gain additional financial support as a result of policies that create further advantages for developers working on green building projects [14]. Although following the LEED requirements brings many benefits for both the project's design performance and its community value, compliance with these requirements does add to the cost (1-9%) and is often challenging for the project team [1,2,10,15]. These challenges include a more complicated design process that involves many additional field cooperation requests, limited budgets, and the need to comply with the LEED construction document requirements [2,16]. To address these issues and improve the overall performance of the building design stage, an investigation of the green strategies that will be incorporated at an early stage of the integrated design process has been recommended by the USGBC and other experts [2,13,17]. During this period, the project team needs to orient and evaluate the design, future construction, and operation plan for the project based on the framework of nine LEED categories and the various credits they contain [10]. After meeting the requirements of the chosen credits, points are awarded for those achieved for each LEED criterion; the appropriate certification level (Platinum, Gold, Silver, Certified, or noncertified) is then be awarded based on the total points achieved [17]. The wide variety of credits/strategies and the flexibility of LEED creates many options for project teams developing sustainable buildings [18], so selecting the most appropriate target LEED credits out of the various options is an essential yet challenging problem for LEED project managers who are also juggling limited budgets, tight project schedules, and factors associated with the unique location and climatic characteristics of their building site [19]. Not surprisingly, there have been a number of studies suggesting methods to support those making these decisions at an early stage in the process when these decisions will have the greatest impact [13,20]. However, challenges remain due to a lack of information/understanding, the high level of expert collaboration required, and the time and cost limitations typically experienced in the early project phase.