Circular
Circular stairs are available in two varieties, supported and freestanding.

Supported staircases have weight-bearing walls arranged underneath them. These staircases are less costly than similar freestanding units because of the reduced number of laminations required to provide strength and rigidity.

A freestanding staircase does not have any intermediate supports. It must bear its own weight and provide rigidity without the benefit of structural supports such as a wall. Because of this, freestanding stairs require additional laminations for structural integrity.
Flared
As their name suggests, these stairs are flared at the bottom. In most cases it is only the first several treads and risers that are flared with the remainder of the staircase being either straight or L-shaped.
Spiral
A spiral stair uses a center pole to conserve floor space. This makes them ideal for attics, lofts, second floor studios, and multilevel decks. They are frequently used in renovation work to create additional space in tall buildings. They are described in degrees of rotation and may turn more than one full rotation from bottom to top. Pictured here is our "Omega" spiral exclusive to Harmonson Stairs.
When considering this type of stair system, be sure to check with your local building officials to see which codes you will be required to follow.
Straight
Most homes use straight-run or L-shaped stairs because they’re versatile and relatively easy to build. They cost much less than a similar circular or flared staircase, and don’t require as much floor space. Their simple design creates an unpretentious look that will fit in any home.