From the lines that have been leveled and squared to the grade, plumb down for the excavation.

Cut a stake the length of intended depth of the basement from the grade line to the basement floor - allowing for the thickness of cement floor, excavate the depth of this stake from the grade line. All measurements for depth of basements, walls, piers, footings, etc., are taken from the grade line.

Leave an approach at one end to draw out the ground. When all dirt is removed except the approach, draw the line in place, plumb down, and excavate the balance with a shovel. Where the bank is to be used for the outside form of a concrete wall, excavate plumb with the wall lines, but where forms are used on both sides, the depth of the wall, excavate the outside of the wall lines 8" to V to admit the forms.