To take off and land about ten by ten meters (100 square meters) will be required, necessary safety distance is already included. Especially in big cities, there are many large flat roofs, e.g on supermarkets, office buildings, hotels, event centers and especially on parking garages. They would be suitable as take-off and landing sites. This is because our drones are very light: single-seaters have a maximum takeoff weight – including the passenger – of 360 kilograms, and two-seaters 520 kilograms. Most flat roofs are designed for much higher loads. So they would not need to be retrofitted.