The invention provides a novel middle-column-supported additionally-arranged
elevator capable of directly reaching an original gate of a resident. The additionally-arranged
elevator is arranged on theouter side of an old building; and according to the additionally-arranged
elevator, a stair middle main supporting column from the ground to the highest layer is built in the turning position of an original stair
handrail and the position beside the turning, the supporting column is used for supporting a stair-free walkway on one side and a stair cross beam and
stairs on the other side, the stair-free walkway is arranged between a gate platform and an elevator gate platform, and stair sections of the
stairs on the other side are rebuilt to be connected with the elevator gate platform. The additionally-arranged elevator has the effects that the resident does not need to walk up and down one step of the
stairs any more when taking the elevator, and the problem that the old people walk up and down the stairs is thoroughly solved; an elevator walkway in front of a
living room is not built, the cost is reduced, and the problem of lighting of the
living room is prevented by the elevator walkway is solved; an original gate can be continued using, a new gate is not needed to be built, the original
layout of the
living room can not be influenced, the resident does not need to spend money to re-decorate the living room, a window and the new gate, a special temporary walkway does not need to be built, and in the construction period, the resident can walk up and down the stairs smoothly and does not need to move to another place temporarily.