The present invention relates to a system and a method for weighing a section of a structure (1). The system comprises at least one hydraulic weight sensor device (3), adapted to be placed in at least one slot (2) under the section, a pressure sensor (7) for measuring the pressure in the at least one weight sensor device (3), and a hydraulic system comprising at least one pump unit (5) and at least one valve unit (6) for pumping hydraulic fluid to and from the at least one hydraulic weight sensor device (3) through a hydraulic line (4). The system further comprises a distance sensor (10) for measuring the height of the slot (2), a control circuit device (20) for calculating the weight of the section based on measured data received from the pressure sensor (7), and for balancing the section on the basis of the measured data received from the pressure sensor (7) and the distance sensor (10) by controlling the pump unit (5) and the valve unit (6).