The cantilever stair plug-in function can create a double run or single run stair in SketchUp. The relevant parameters such as the height of the stair, the clear width of the stair run, the total number of steps, the number of one run, the thickness of the stair slab, the thickness of the platform slab, the thickness of the partition wall, the platform beam, the thickness of the handrail wall / the height of the wall can be customized to generate a standard building suitable for the cantilever structure