As part of the Energy Efficient Buildings Hub Year 3 subtask on occupant behavior and decision making, a research team performed a user needs assessment and a preliminary evaluation of the effectiveness of a novel human-machine interface (HMI) for a building control and diagnostics system. The HMI was developed by a different research team at the Hub, and the two teams worked closely together in a highly iterative process of design-and-feedback that allowed rapid progress from concept to pilot implementation. Funding for this project ended sooner than expected on January 31, 2014, so there is more that could be done regarding implementation and evaluation. If resources become available in the future, then field deployments of the HMI could be evaluated and the resulting information used to further refine the interface.