Reversible window assembly comprising: - a window frame comprising four frame elements: an upper frame element, a lower frame element and two side frame elements (2b,2d), - a window sash comprising four sash elements: an upper sash element, a lower sash element and two side sash elements (3b,3d), and where the window frame elements and the window sash elements are arranged such that a fitting cavity which stretches the length of the upper sash element is provided between the upper frame element and the upper sash element in the closed position of the window assembly, and - two reversible window fittings, each reversible window fitting arranged between one side frame element and one side sash element, and where each reversible window fitting comprises: - a rail mounted on a side frame element (2b,2d), and - a slider having a sliding portion slidably arranged in said rail and said slider being rotatably connected to the window sash, wherein the axis of rotation between the slider and the window sash is offset from the longitudinal axis of the rail characterized in that two recesses (9,B) are provided in the upper frame element in extension of the two rails of the two reversible window fittings, in order to allow the sliding portion of the slider of each reversible window fitting to enter one of the recesses in the closed position of the window assembly such that the top portion of the sliding portion of the slider is arranged above the top most surface of the inner surface of the fitting cavity which stretches the length of the upper sash element in the closed position of the window assembly. - a window frame comprising four frame elements: an upper frame element, a lower frame element and two side frame elements (2b,2d), - a window sash comprising four sash elements: an upper sash element, a lower sash element and two side sash elements (3b,3d), and where the window frame elements and the window sash elements are arranged such that a fitting cavity which stretches the length of the upper sash element is provided between the upper frame element and the upper sash element in the closed position of the window assembly, and - two reversible window fittings, each reversible window fitting arranged between one side frame element and one side sash element, and where each reversible window fitting comprises: - a rail mounted on a side frame element (2b,2d), and - a slider having a sliding portion slidably arranged in said rail and said slider being rotatably connected to the window sash, wherein the axis of rotation between the slider and the window sash is offset from the longitudinal axis of the rail characterized in that two recesses (9,B) are provided in the upper frame element in extension of the two rails of the two reversible window fittings, in order to allow the sliding portion of the slider of each reversible window fitting to enter one of the recesses in the closed position of the window assembly such that the top portion of the sliding portion of the slider is arranged above the top most surface of the inner surface of the fitting cavity which stretches the length of the upper sash element in the closed position of the window assembly. - a rail mounted on a side frame element (2b,2d), and - a slider having a sliding portion slidably arranged in said rail and said slider being rotatably connected to the window sash, wherein the axis of rotation between the slider and the window sash is offset from the longitudinal axis of the rail