Charles Ellicott Commentary Leviticus 1:11

"And he shall kill it on the side of the altar northward before Jehovah: and Aaron`s sons, the priests, shall sprinkle its blood upon the altar round about." — Leviticus 1:11 (ASV)

On the side of the altar northward. —As the place for the refuse was on the east side , as the laver stood on the west side, and as the ascent to the altar was on the south side, the north side was the most convenient for slaughtering the victims. This also applies to the sin and trespass offerings (Leviticus 4:24, Leviticus 4:29, Leviticus 4:33, Leviticus 6:25, Leviticus 7:2, Leviticus 14:13, and other passages).