View Images Library Photos and Pictures. How to Choose a Spiral Staircase or Helical Design - Build It curved-stair-layouts.png (539×600) | Stair plan, Spiral staircase plan, Stair layout Drawing, Plan Development and Elevation for a Spiral Staircase that Turns to the Right | Objects | Collection of Cooper Hewitt, Smithsonian Design Museum How to Design a Spiral Staircase?