Door kit comprising: - a frame suitable for being fixed in a secondary frame which is fixed to a wall and comprises three pieces, namely two side pieces and one head piece; said frame comprising three pieces, namely two side pieces, one for each side piece, and one head piece for said head piece; each piece of the frame comprises an outer face adapted to face the respective piece of the secondary frame, an inner face and two side faces; - at least one molding that can be applied to one side of the frame and comprises three jambs, each one being suitable for being coupled with one of said side faces of the pieces of the frame; each jamb comprising: - a first section suitable for completely covering the respective piece of the secondary frame, for partially covering the wall, and for partially covering the portion of the side face of the respective piece of the frame; and - a second section aligned with the first section and adapted to abut the side face of the respective piece of the frame; and, - at least one alternative molding that can be applied to the same side of the frame as an alternative to said molding; said alternative molding comprising three jambs, each one of them being suitable for being coupled to the side face of the respective piece of the frame; wherein the side face of each piece of the frame comprises a notch that extends longitudinally along the entire length of said piece; each jamb of the at least one alternative molding comprises an L-shaped cross-section comprising: - a first section suitable for completely covering the respective piece of the secondary frame, for partially covering the wall, and for partially covering the portion of the side face of the respective piece of the frame; and - a second section orthogonal to said first section and adapted to be slidingly inserted inside the notch of the side face of the respective piece of the frame, wherein the side face of the piece of the frame comprises a seat and the jamb of of the at least one molding comprises a seat obtained on a face of the jamb suitable for facing the piece of the frame; said kit comprising coupling means adapted to be arranged in the seat of the side face of the piece of the frame and in the seat of the jamb of the at least one molding for coupling said jamb to said side face of the piece of the frame. - a frame suitable for being fixed in a secondary frame which is fixed to a wall and comprises three pieces, namely two side pieces and one head piece; said frame comprising three pieces, namely two side pieces, one for each side piece, and one head piece for said head piece; each piece of the frame comprises an outer face adapted to face the respective piece of the secondary frame, an inner face and two side faces; - at least one molding that can be applied to one side of the frame and comprises three jambs, each one being suitable for being coupled with one of said side faces of the pieces of the frame; each jamb comprising: - a first section suitable for completely covering the respective piece of the secondary frame, for partially covering the wall, and for partially covering the portion of the side face of the respective piece of the frame; and - a second section aligned with the first section and adapted to abut the side face of the respective piece of the frame; and, - at least one alternative molding that can be applied to the same side of the frame as an alternative to said molding; said alternative molding comprising three jambs, each one of them being suitable for being coupled to the side face of the respective piece of the frame; - a first section suitable for completely covering the respective piece of the secondary frame, for partially covering the wall, and for partially covering the portion of the side face of the respective piece of the frame; and - a second section orthogonal to said first section and adapted to be slidingly inserted inside the notch of the side face of the respective piece of the frame, wherein the side face of the piece of the frame comprises a seat and the jamb of of the at least one molding comprises a seat obtained on a face of the jamb suitable for facing the piece of the frame; said kit comprising coupling means adapted to be arranged in the seat of the side face of the piece of the frame and in the seat of the jamb of the at least one molding for coupling said jamb to said side face of the piece of the frame.