If you have plans to build a deck that will have more than one level or will be more than about 15 inches above the ground, you'll need stairs.
Stairs can be one of the more challenging aspects of a deck-building project.
When building stairs, you not only need to be a good craftsperson, but, in many cases, you need to have a solid background in both math and geometry. However, as you will learn, not all stair-building projects need to be complicated. It's an area at the bottom of, top of or between flights of stairs. Although the straight-stair type is among the most popular and easiest to construct, it is just one of many layouts. No sense in skimping when it comes to stair width.