Energy harvesting technology is being developed with the goal of using ambient energy to meet small energy requirements. From the dynamics viewpoint, the most interesting is the use of motion and vibration to gain useful energy. This paper discusses the use of human motion energy harvesting methods through a public building with the goal of reducing the demand for electrical energy from the city grid. The energy of human motion can be harvested through various means using piezoelectricity or generators. Piezoelectricity is the electrical charge occurring in crystal materials amidst mechanical stress. A fictional insurance and certification company is used as an example for a public building. We can assume the annual electrical energy usage and the human traffic through the building. The first solution is the use of floorboards with piezoelectric harvesters. This boards are built into stairs and the floor of the main room and corridors. The device consists of a board placed above a metal frame. There is a lever mechanism on each end of the frame which is connected to the other one with a weight. They hold the board with a small gap above the frame. When the board is stepped on, the levers lift the weight which on its way up bends the harvesters. The harvesters are cantilever type and are paired with electrical circuits which converts the piezoelectric charge into usable current. When the cantilevers are agitated, they turn into damped flexion oscillators. These oscillations are converted into electrical energy which is collected into the main electrical grid. The second solution is the installation of a generator into the revolving doors. Door turns are converted via a gear train into the operating number of rotations per minute of the generator which produces the electrical energy for the building’s electrical grid. The mechanism shouldn’t require much effort for movement. In the final cost-effectiveness comparison, it turns out that all systems manage to cover just a fraction of one percent of the building’s daily energy requirements. The time until full return on investment is measured in many years. The concept used with the revolving doors gives the best results. In conclusion, human motion energy harvesting technology is most efficient when used where there is a small energy requirement and a large amount of human motion.