A sliding window for a building, comprising: - a fixed frame, - at least one leaf (3a, 3b), - a motorized drive device for moving the leaf by sliding relative to the fixed frame, ∘ the motorized drive device comprising: ▪ an electromechanical actuator, the electromechanical actuator comprising an electric motor and an output shaft, the rotation axis of the output shaft being parallel to the sliding direction of the leaf relative to the fixed frame, ▪ a flexible element, the flexible element being moved by the electromechanical actuator, the flexible element comprising a first strand and a second strand, ▪ a carriage, the carriage being, on the one hand, attached on the first leaf and, on the other hand, connected to the flexible element, ▪ a winding pulley of the flexible element, the winding pulley being rotated by the output shaft of the electromechanical actuator, one end of the first strand of the flexible element being connected to a first part of the winding pulley, one end of the second strand of the flexible element being connected to a second part of the winding pulley, characterized in that the winding pulley and the output shaft of the electromechanical actuator have a same rotation axis, and in that the motorized drive device further comprises: - a first angle transmission mechanism cooperating with the first strand of the flexible element, so as to guide the first strand of the flexible element relative to the first part of the winding pulley, and - a second angle transmission mechanism cooperating with the second strand of the flexible element, so as to guide the second strand of the flexible element relative to the second part of the winding pulley. - a fixed frame, - at least one leaf (3a, 3b), - a motorized drive device for moving the leaf by sliding relative to the fixed frame, ∘ the motorized drive device comprising: ▪ an electromechanical actuator, the electromechanical actuator comprising an electric motor and an output shaft, the rotation axis of the output shaft being parallel to the sliding direction of the leaf relative to the fixed frame, ▪ a flexible element, the flexible element being moved by the electromechanical actuator, the flexible element comprising a first strand and a second strand, ▪ a carriage, the carriage being, on the one hand, attached on the first leaf and, on the other hand, connected to the flexible element, ▪ a winding pulley of the flexible element, the winding pulley being rotated by the output shaft of the electromechanical actuator, one end of the first strand of the flexible element being connected to a first part of the winding pulley, one end of the second strand of the flexible element being connected to a second part of the winding pulley, characterized in that the winding pulley and the output shaft of the electromechanical actuator have a same rotation axis, and in that the motorized drive device further comprises: ∘ the motorized drive device comprising: ▪ an electromechanical actuator, the electromechanical actuator comprising an electric motor and an output shaft, the rotation axis of the output shaft being parallel to the sliding direction of the leaf relative to the fixed frame, ▪ a flexible element, the flexible element being moved by the electromechanical actuator, the flexible element comprising a first strand and a second strand, ▪ a carriage, the carriage being, on the one hand, attached on the first leaf and, on the other hand, connected to the flexible element, ▪ a winding pulley of the flexible element, the winding pulley being rotated by the output shaft of the electromechanical actuator, one end of the first strand of the flexible element being connected to a first part of the winding pulley, one end of the second strand of the flexible element being connected to a second part of the winding pulley, characterized in that the winding pulley and the output shaft of the electromechanical actuator have a same rotation axis, and in that the motorized drive device further comprises: ▪ an electromechanical actuator, the electromechanical actuator comprising an electric motor and an output shaft, the rotation axis of the output shaft being parallel to the sliding direction of the leaf relative to the fixed frame, ▪ a flexible element, the flexible element being moved by the electromechanical actuator, the flexible element comprising a first strand and a second strand, ▪ a carriage, the carriage being, on the one hand, attached on the first leaf and, on the other hand, connected to the flexible element, ▪ a winding pulley of the flexible element, the winding pulley being rotated by the output shaft of the electromechanical actuator, one end of the first strand of the flexible element being connected to a first part of the winding pulley, one end of the second strand of the flexible element being connected to a second part of the winding pulley, - a first angle transmission mechanism cooperating with the first strand of the flexible element, so as to guide the first strand of the flexible element relative to the first part of the winding pulley, and - a second angle transmission mechanism cooperating with the second strand of the flexible element, so as to guide the second strand of the flexible element relative to the second part of the winding pulley.