Systems and methods for controlling windows with variable light transmission are disclosed. In one embodiment, a system includes a sensor adapted to receive a light intensity, a user input device adapted to receive a user input value, a window having a variable transmissivity portion, and a control system. The control system is operatively coupled to the sensor, the user input device, and the window, and is adapted to receive the light intensity and user input value and to adjust a transmission level of the variable transmissivity portion of the window based on at least one of the light intensity and the user input value. The sensor includes a sensor adapted to receive a light intensity, a temperature, a humidity, or other environmental variables. In other embodiments, the system also includes a ventilation system, an air conditioning system, or a humidity control system.