Thank you. I think we are arriving at something. I do not believe we can add the shelving at the far left side, as the riser is not 15" from the wall. The drawers going on the flat floor are 15" in depth.I would match the angle and then go say 8" rise per step and let the run be whatever it comes out to be. Remember when making the first step you have to subtract the thickness of the tread from the rise on the stringer. Best way is to make a scale drawing of what you have first. 1to1 is best if you have someplace large enough to draw it out.