Wooden Spiral Stairs
Any spiral staircase can be measured quite easily. Measure hard floor to hard floor, and then decide on the diameter you would like. You can buy pre-made kits and assemble your spiral staircase yourself, or you can build it by hand.
Wooden Spiral Staircase with Steel
In some cases, you may need a metal frame for your wooden spiral staircase, such as for use outdoors. You can buy the center pole and risers and make the treads by hand, or buy a kit for the entire staircase.
Specifications and Zoning
Wherever you are installing your spiral staircase, always make sure you have obtained the correct permits and are zoned for such an installation. Ensure you have the necessary clearance, for headroom, and for fingers and hands around banisters.