Create a stair by assembling common run, landing, and support components.
To create a component-based stair, you work in a stair assembly edit mode to add common and custom sketched components. In stair assembly edit mode, you can directly assemble components in a plan or 3D view. Tiling the views can give you a complete picture of the stair model as you assemble it. A component-based stair can consist of
Notice in the following image that you can create a stair where the assembled components overlap:

You can assemble multiple runs leading to the same landing, for example, a T-shaped stair:

Components in a stair assembly are independent, but also have an intelligent relationship to each other to support design intent. For example, if steps are removed from one run, steps are added to connected runs to maintain the overall stair height.
Because the stair is built with components, the individual parts can be controlled separately; they can be
Create a common run component in a plan or 3D view.
Create a landing between 2 runs in a stair assembly.
Create a side support by picking run or landing edges.
Create a run or landing component by sketching the shape.
Modify stair, run, landing, and support components.
Annotate stair components and control visibility of elements.