A system may determine a number of floors of a building based on image data of the building. The system may determine a background color of a façade of the building shown in the image data. Using this background color, predefined deviations may then be detected that form the background color in the façade of the building. A mean number of predefined deviations in the vertical direction of the façade of the building may be determined, and the number of floors of the building based on the determined mean number of predefined deviations can be then be deduced.