Abstract: A corner system for log cabin siding construction over building frame walls and corners gives the appearance of full log construction. Elongate wall siding pieces are applied over the walls with a flat inner side facing the wall and a curved outer side for simulated "log" appearance. Corner siding pieces are applied over the corners with wall covering portions in horizontal alignment with wall siding pieces, and projecting log end portions extend beyond the building corner. Each corner siding piece is cut from a single piece of wood without a joint or seam and with continuous grain between the wall covering portion and the projecting log end portion of a corner siding piece. Wall siding pieces and corner siding pieces are formed with edge configuration of overlapping "ship-lap" siding or interfitting tongue and groove siding.