The window blind is one of the most functional and widely used shading devices for reducing solar heat gain through windows by blocking direct solar penetration from entering the room. The objective of energy savings in buildings is to attain not only minimum energy consumption but also to provide maximum comfort for occupants. In a previous survey [8], it was shown that window blinds are usually rolled down most of the time and that they tend to be too low during some periods, resulting in the unnecessary blocking of daylight, solar heat, and view. The purpose of this paper is to provide a control strategy for an automated blind that can achieve visual comfort and energy savings in buildings. Simulations were performed to investigate the environmental performance of control strategies. A thermal model was developed with Matlab/Simulink to implement various window blind controls. Also, RADIANCE software was used for daylight simulations. The results of the simulations show that the window blind vertical position is an important control variable and there is energy savings potential through taking maximum advantage of daylight in buildings. In order to validate the control system, a preliminary experiment was performed in a full-scale typical office space.