Free... For a single straight flight from one level to the next.
Subscriber Only... For two or more straight flights intersecting at an angle other than 90 degrees.
Subscriber Only... For two straight flights intersecting at a 90 degree angle.
Subscriber Only... Two straight flights turning back 180 degrees, sharing a common center support wall.
Subscriber Only... Two flights turning back 180 degrees with one landing and an open center well.
Subscriber Only... Three straight flights turning back 180 degrees with two landings and an open center well.
Subscriber Only... Stairs where inside and outside stringers are arc segments of two concentric circles in plan.
Subscriber Only... Stairs with one or two straight flights combined with a circular flight.
Subscriber Only... Stairs where either the inside stringer, outside stringer, or walkline is a segment of an ellipse in plan, with the remaining two being offset forming ovals.
Subscriber Only... Stairs winding around a center support.