Embodiments are disclosed for a method. The method includes generating statistical models of circadian rhythms based on circadian rhythm data generated by mobile computing devices of occupants of a building having a building automation system. The method also includes identifying room occupants of a room disposed within the building. Additionally, the method includes determining ambient settings for an ambient system operated by the building automation system based on a subset of the statistical models, wherein the subset corresponds to the identified room occupants. The method further includes determining a trade-off ambient setting based on the ambient settings.