A stiffened frameless sash comprising, (a) an outer glazing (1 01) defining an outer glazing surface having an outer glazing area and bounded by an outer glazing perimeter, (b)an inner glazing defining an inner glazing surface having an inner glazing area larger than or equal the outer glazing area, and bounded by an inner glazing perimeter, the inner glazing being separated from the outer glazing by an inner width, W10g, (c) an intermediate glazing parallel to both inner and outer glazings and bounded by an intermediate glazing perimeter, the intermediate glazing being positioned between the inner and outer glazings, separated from the outer glazing by an outer gap and from the inner glazing by an inner gap,, (d)an outer peripheral spacer separating the outer glazing from the intermediate glazing and comprising an outer gap side defining an outer gap perimeter of the outer gap, and comprising a peripheral side opposite the outer gap side, (e)an inner peripheral spacer separating the inner glazing from the intermediate glazing and comprising an inner gap side defining an inner gap perimeter of the inner gap, and comprising a peripheral side opposite the inner gap side, (f) a peripheral volume extending along the whole of the inner and outer glazing perimeters, and comprised between the inner and outer glazings and from the peripheral sides of the inner and outer peripheral spacers to the corresponding inner and outer glazing perimeters, characterized in that, the stiffened frameless sash further comprises, • a first peripheral profile (151, 152) fixed to or integral with the peripheral side of one only of the inner peripheral spacer or of the outer peripheral spacer, the first peripheral profile protruding into the peripheral volume and defining a support surface (151s, 1 52s) facing outwards, said support surface being transverse, preferably normal to the outer glazing surface and extends along a whole length of the corresponding inner or outer peripheral spacer, and in that, • a portion of the peripheral volume excluding the first peripheral profile (151, 152) is filled with a structural resin defining a resin surface, with a whole of the support surface of the first peripheral profile remaining exposed and is free of structural resin or is covered by a layer of the structural resin having a mean thickness of not more than 2 mm, preferably not more than 1 mm. (a) an outer glazing (1 01) defining an outer glazing surface having an outer glazing area and bounded by an outer glazing perimeter, (b)an inner glazing defining an inner glazing surface having an inner glazing area larger than or equal the outer glazing area, and bounded by an inner glazing perimeter, the inner glazing being separated from the outer glazing by an inner width, W10g, (c) an intermediate glazing parallel to both inner and outer glazings and bounded by an intermediate glazing perimeter, the intermediate glazing being positioned between the inner and outer glazings, separated from the outer glazing by an outer gap and from the inner glazing by an inner gap,, (d)an outer peripheral spacer separating the outer glazing from the intermediate glazing and comprising an outer gap side defining an outer gap perimeter of the outer gap, and comprising a peripheral side opposite the outer gap side, (e)an inner peripheral spacer separating the inner glazing from the intermediate glazing and comprising an inner gap side defining an inner gap perimeter of the inner gap, and comprising a peripheral side opposite the inner gap side, (f) a peripheral volume extending along the whole of the inner and outer glazing perimeters, and comprised between the inner and outer glazings and from the peripheral sides of the inner and outer peripheral spacers to the corresponding inner and outer glazing perimeters, • a first peripheral profile (151, 152) fixed to or integral with the peripheral side of one only of the inner peripheral spacer or of the outer peripheral spacer, the first peripheral profile protruding into the peripheral volume and defining a support surface (151s, 1 52s) facing outwards, said support surface being transverse, preferably normal to the outer glazing surface and extends along a whole length of the corresponding inner or outer peripheral spacer, and in that, • a portion of the peripheral volume excluding the first peripheral profile (151, 152) is filled with a structural resin defining a resin surface, with a whole of the support surface of the first peripheral profile remaining exposed and is free of structural resin or is covered by a layer of the structural resin having a mean thickness of not more than 2 mm, preferably not more than 1 mm.