Stair building is one of the most complex aspects of carpentry. My experience is that a good and accurate design is the only way to approach any complex geometry problem.Without CAD software, stairs can be laid out on paper, using ordinary drafting tools. When complete, you can use a ruler to take measurements from the drawing, measurements that would be difficult and time-consuming to calculate. The distance from the deck surface to the floor, sidewalk or deck surface below is called the total rise.Laying this out is much easier on paper (or a CAD system) than trying to create layout lines on the actual project. I suppose you could draw layout lines on the deck support posts, or you could drive some stakes into the ground and mark them.spiral staircases are constructed on a three inch (internal diameter) steel pipe. The treads have a 3 5/8th inch hole in them allowing them to slip fit over the pipe. Between each tread there are short pieces of three and one half inch (internal diameter) pipe which are also slipped over the center pole pipe. After the landing is placed on top of the staircase, a threaded pipe is screwed onto the center pole pipe which tightens everything in place. These spiral stair plans go into detail about how to measure, construct, then assemble this spiral staircase into several different situations