The invention relates to a flap system (12) for a building (10), which is designed in particular as a ventilation device, sun screen, insulation protection, privacy screen and/or weather protection, comprising a support arm (16), by means of which a support axis (18) is mounted in a manner that is translationally fixed and rotatable about the longitudinal axis thereof； a flap (14) that is connected for conjoint rotation with the support axis (18) and thereby pivotable, wherein the support axis (18) is arranged between a top end and a bottom end of the flap (14)； a frame structure (24) being used as a transmission which is connected to the flap (14)； a driver unit (30) which is mounted to move in a translational manner in the vertical direction of the flap system (12) and which is connected in an articulated manner by means of a compensating element (40) to the frame structure (24) so that a translational movement of the driver unit (30) causes the flap (14) to pivot； a drive device for moving the driver unit (30).
