Abstract: The invention concerns an energy management method in a building including a lifting installation with a mobile car in a shaft and a ventilation passage between the shaft and the atmosphere. The method includes the monitoring of at least one state parameter of the lifting installation; the evaluation, in a control unit, of the necessity to ventilate the shaft based on at least one state parameter; the switching of an obturator element associated with the ventilation passage from an open position, wherein the ventilation passages is essentially open, to a closed position, wherein the ventilation passages is at least partially obturated, only when the evaluation indicates that ventilation of the shaft is not required, the obturator element being prestressed in its open position. The invention also concerns an energy management system designed to implement the method according to. The present method and system are particularly suitable for installation of a lift in a low-energy or passive building.