Personal control through thermostats is well understood to increase thermal comfort; however, the usability of thermostats can play a role in realizing these benefits. This thesis contributes to the understanding of how thermostat interfaces and the operation of HVAC control systems can affect perceived control in offices. Phase 1 applied an analysis of the building performance combined with a survey to identify barriers to usability in the offices. Phase 2 involved the development and implementation of three features, using design techniques from the field of human factors, which addressed the usability issues found in Phase 1. Phase 3 aimed to measure the operation and gather feedback on these implemented features. The research was performed on 25 offices in an institutional building. It is expected that the issues found in this building are widespread, and the solutions developed can be iterated and applied to other institutional and commercial buildings with offices.