Potable water system for a building, comprising a hot water supply line, a cold water supply line, a plurality of water consumers branching of from the hot water supply line and the cold water supply line, wherein each water consumer has a mixing valve having a first inlet connected to the hot water supply line, a second inlet connected to the cold water supply line and an outlet connected to a withdrawal line conducting mixed water to a point of withdrawal of the respective water consumer, a controller receiving an actual value of the hot water temperature and an actual value of the cold water temperature, wherein the controller generates at least one control signal for preventing and/or counteracting microbiological growth within the potable water system, characterized in that each water consumer has at least one temperature sensor (24, 25) assigned to the withdrawal line of the respective water consumer for measuring an actual value of at least one consumer individual mixed water temperature (T1, T4) of each water consumer, each water consumer has a flow sensor assigned to the withdrawal line of the respective water consumer for measuring an actual value of a consumer individual past mixed water consumption of each water consumer, the controller receives in addition to the hot water temperature and the cold water temperature an actual value of the at least one consumer individual mixed water temperature (T1, T4) of each water consumer and an actual value of the consumer individual past mixed water consumption volume of each water consumer, the controller generates for each water consumer at least one water consumer individual control signal for preventing and/or counteracting microbiological growth within the potable water system. a hot water supply line, a cold water supply line, a plurality of water consumers branching of from the hot water supply line and the cold water supply line, wherein each water consumer has a mixing valve having a first inlet connected to the hot water supply line, a second inlet connected to the cold water supply line and an outlet connected to a withdrawal line conducting mixed water to a point of withdrawal of the respective water consumer, a controller receiving an actual value of the hot water temperature and an actual value of the cold water temperature, wherein the controller generates at least one control signal for preventing and/or counteracting microbiological growth within the potable water system, characterized in that each water consumer has at least one temperature sensor (24, 25) assigned to the withdrawal line of the respective water consumer for measuring an actual value of at least one consumer individual mixed water temperature (T1, T4) of each water consumer, each water consumer has a flow sensor assigned to the withdrawal line of the respective water consumer for measuring an actual value of a consumer individual past mixed water consumption of each water consumer, the controller receives in addition to the hot water temperature and the cold water temperature an actual value of the at least one consumer individual mixed water temperature (T1, T4) of each water consumer and an actual value of the consumer individual past mixed water consumption volume of each water consumer, the controller generates for each water consumer at least one water consumer individual control signal for preventing and/or counteracting microbiological growth within the potable water system.