When choosing from one of the four pre-designed stair drawings all plans can be built to fit from a 9' floor to floor height to a 12' floor to floor height and anywhere in between. All stairs can be freestanding on one side or both sides of the stair case. All four of these stair designs, radius & stair tread dimensions must remain the same. Depending upon floor height, treads will be added or removed. When choosing a curb style stair, the stairs width will become 4" narrower per side.