In the last decades, the improvement of innovative solutions on windows to achieve sustainability within the built environment is considered as a principal issue. Windows have long been used in buildings for daylight and ventilation. From many studies, health, comfort, and productivity are improved by the well-ventilated indoor environment, because ventilation dilutes the indoor concentration of contamination for indoor air quality. Also, too high indoor air velocity is perceived as draft or chilly, but too low air velocity may create stuffiness. Besides, natural ventilation is one of the most prominent issues of energy consumption within buildings. In summer, cooperated with chimney effect, natural ventilation can reduce the use of the cooling system. Even in winter, the operable window should dynamically adjust the ventilation rates based on actual population to control human CO2 emissions. Consequently, the use of heating, ventilation and air conditioning (HVAC) system will be reduced. Windows influence the natural ventilation of a building directly and guarantee indoor comfort level, indoor air quality and minimize energy consumption. Windows can be opened manually, or center controlled mechanically. Unreachable windows for instance, in atrium or skylight, are opened by window actuators which are centrally controlled or passively controlled for the reason to optimize indoor comfort. There are advantages using window actuators in terms of controlled natural ventilation. Window actuators can make a significant contribution to a building’s indoor environment and energy performance. Today it should be easy for the window to control opening sizes for adapting wind direction and wind load, meanwhile, the inlet air velocity should be possibly manipulated to optimize indoor air velocity. In this thesis, the dynamic way of opening windows by using window actuators for the reason of manipulating inlet wind velocity and adapting wind direction and load will be developed. Inspired by that air velocity varies on a curved surface because of curvature changing, inlet air velocity can be manipulated continuously and smoothly by changing window curvature.