In the roof window, the hinge assembly (9) comprises a coupling unit (95) connected to or connectable to the frame (2) and configured to be connected to the hinge unit (91) in the mounted condition of the roof window (1). In an installation condition of the roof window (1), the hinge unit (91) is connected to the sash (3) and the coupling unit (95) is connected to the frame (2).

A method for mounting a roof window (1) in a roof structure (11) comprising a roofing material (112), said roof window comprising a frame (2), a sash (3) carrying a pane element (4), where the method comprises the steps of A) Arranging the roof window (1) in an opening in the roof structure (11), B) Arranging a plurality of flashing members so that they cover a joint between the frame (2) of the roof window (1) and the roof structure (11) with a top flashing member (1011) extending along the top frame member (21), a bottom flashing member (1014) extending along the bottom frame member (24), and at least two side flashing members (1012, 1013) extending along the side frame members (22, 23), and during step B) a flange (1017) of at least one side flashing member (1012, 1013) is inserted into a flashing reception groove (85) in the outer side (20o) of at least one side frame member (22, 23), said flashing reception groove extending in the length direction (L) of the side frame member.

In the roof window, a hinge assembly (9) is provided to allow the sash (3) to be tophung in a first operational condition corresponding to normal use in that the sash (3) is intended to be rotated about a substantially horizontal first hinge axis () at or near the top frame member (21) and top sash member between a closed position and an open position, the hinge assembly (9) comprising a hinge unit (91) with a frame hinge part (92) connected to or connectable to at least the top frame member (21), a sash hinge part (93) connected to at least the top sash member, and a hinge pin (94) connecting the frame hinge part (92) with the sash hinge part (93). The frame hinge part (92) is connected to the top frame member (21) and provided with a receiving structure (922) for the hinge pin (94) defining the first hinge axis (), and the sash hinge part is connected to the top sash member (31) and provided with a receiving structure (932) for the hinge pin (94), such that the hinge unit (91) forms a pin-and-barrel hinge.