Energies 2015,8 10998 occupancy energy-use behaviors can significantly impact total annual energy use on the order of 150 percent for the commercial sector [8].Occupant actions can also lead to excessive and unnecessary energy consumption [28].In the United States'commercial built environment,less than half of most buildings'appliances and systems are turned off by occupants after operational hours [29].Due to the fact that there are more non-working hours in a week than working hours,such behaviors can lead to more energy wasted during non-working hours than energy used during working hours [30].In this context,therefore,a growing number of recent studies emphasize the importance of improving occupant energy-use behaviors as a cost-effective approach for saving energy in commercial buildings;such work spans various research communities,including psychology and economics [31].It is of interest to explore how these studies address occupants'behaviors. A glance at the current literature shows that a considerable number of approaches of varying complexity have been proposed to address problems related to occupants'energy-use behaviors in commercial buildings.These approaches in the current literature can be grouped into the following three categories: 1.Monitoring occupant-specific energy consumption:This approach provides individual occupant energy-use information in order to understand the energy behavior of individual occupants. 2. Simulating occupant energy-consuming behaviors:This approach simulates realistic occupancy energy-use behaviors in order to capture and predict how such behaviors influence energy consumption in built environments and how such behaviors impact change over time. 3.Improving occupant energy-consuming behaviors:This approach aims to adjust energy-consuming behaviors among occupants in order to achieve the most ideal energy-saving potential in buildings. These three categories share the ultimate goal of improving occupant energy-use behaviors,and advances in one area are expected to lead to advances in another area.However,despite the clear attention given to research in each category,there has been no attempt to comprehensively review these three areas in order to identify the gaps between them and the potential areas for further research. Motivated by this lack in knowledge,the objective of this paper is to present a detailed,up-to-date review of various algorithms,models,and techniques employed in each area and to provide in-depth understanding on how the current literature in each area can be connected. In the subsequent sections,we will review the literature of each main approach,discuss the gaps within and between each area,and conclude with directions for future research. 2.Monitoring Occupant-Specific Energy Consumption Generally,commercial buildings contain a large number of end-users(i.e.,occupants and appliances). In buildings with a single tenant,a single meter is installed at the main electrical service to measure the total aggregate energy consumption of all end-users.In buildings with multiple tenants,a meter is installed to measure each tenant's aggregate consumption.In either case,the fact that the monitored energy consumption is an aggregate of all the users'and building's appliance(mechanical load,lighting, etc.)load significantly complicates the breakdown of observed energy loads to individual appliances or occupants [32,33].Energies 2015, 8 10998 occupancy energy-use behaviors can significantly impact total annual energy use on the order of 150 percent for the commercial sector [8]. Occupant actions can also lead to excessive and unnecessary energy consumption [28]. In the United States’ commercial built environment, less than half of most buildings’ appliances and systems are turned off by occupants after operational hours [29]. Due to the fact that there are more non-working hours in a week than working hours, such behaviors can lead to more energy wasted during non-working hours than energy used during working hours [30]. In this context, therefore, a growing number of recent studies emphasize the importance of improving occupant energy-use behaviors as a cost-effective approach for saving energy in commercial buildings; such work spans various research communities, including psychology and economics [31]. It is of interest to explore how these studies address occupants’ behaviors. A glance at the current literature shows that a considerable number of approaches of varying complexity have been proposed to address problems related to occupants’ energy-use behaviors in commercial buildings. These approaches in the current literature can be grouped into the following three categories: 1. Monitoring occupant-specific energy consumption: This approach provides individual occupant energy-use information in order to understand the energy behavior of individual occupants. 2. Simulating occupant energy-consuming behaviors: This approach simulates realistic occupancy energy-use behaviors in order to capture and predict how such behaviors influence energy consumption in built environments and how such behaviors impact change over time. 3. Improving occupant energy-consuming behaviors: This approach aims to adjust energy-consuming behaviors among occupants in order to achieve the most ideal energy-saving potential in buildings. These three categories share the ultimate goal of improving occupant energy-use behaviors, and advances in one area are expected to lead to advances in another area. However, despite the clear attention given to research in each category, there has been no attempt to comprehensively review these three areas in order to identify the gaps between them and the potential areas for further research. Motivated by this lack in knowledge, the objective of this paper is to present a detailed, up-to-date review of various algorithms, models, and techniques employed in each area and to provide in-depth understanding on how the current literature in each area can be connected. In the subsequent sections, we will review the literature of each main approach, discuss the gaps within and between each area, and conclude with directions for future research. 2. Monitoring Occupant-Specific Energy Consumption Generally, commercial buildings contain a large number of end-users (i.e., occupants and appliances). In buildings with a single tenant, a single meter is installed at the main electrical service to measure the total aggregate energy consumption of all end-users. In buildings with multiple tenants, a meter is installed to measure each tenant’s aggregate consumption. In either case, the fact that the monitored energy consumption is an aggregate of all the users’ and building’s appliance (mechanical load, lighting, etc.) load significantly complicates the breakdown of observed energy loads to individual appliances or occupants [32,33]