Recent studies have focused on increasing energy efficiency in commercial buildings through technological means (e.g., efficient HVAC systems, sensors and sensing systems). However, most studies underestimate the impact of occupants behavioural choices. Lighting systems account for approximately a fifth of the total electricity consumption in the US; commercial buildings account for 71 percent of such consumption. This paper focuses on human behaviour related energy consumption by investigating the impact of personal control on lighting use in office environments. To effectively examine human energy consumption behaviour, alternative 3D design models of an office are created using an immersive virtual environment to visualize different lighting control features. Participants are brought into these immersive virtual environments by wearing Head-Mounted Displays and are asked to interact within these environments and perform a defined task. Participants were then allowed to control and change the rooms lighting settings based on their preferences in order to perform their assigned task. Unique to our experimental design is the use of immersive virtual environments, enabling measurement and control of a series of design feature isolations and combinations. The work presents the impact of decisions made both during design and operation of buildings on occupants energy related behaviour. The experiment demonstrated that whenparticipants are provided with personal controls for the blinds and the artificial light, there is no significant difference in their preferences between natural and artificial lighting; however participants are significantly more likely to open the blinds remotely if they are only provided with a personal control for the blinds.