The building codes that california uses are based on those found in the uniform building code or ubc instituted in 1927.
Building open riser stairs.
Locate staircases in a prominent position and visible from the building entry and lift waiting areas.
Lay out the stairs by drawing on the outside of the square sliding the square along until it meets the last mark to learn how to build steps.
Draw attention to a staircase by using higher levels of local lighting.
Maximum 7 3 4 inch stair riser height.
Ubc standards for stairs cover many aspects of stair and handrail design and installation including those required by the americans with disabilities act of 1990 and subsequent revisions of the ubc.
Use the narrow part of the square for clamping the riser gauge and the wider part for the 10 1 4 in.
Minimum 10 inch stair tread depth with nosing or minimum 11 inches with no nosing.
Stair treads shall be of uniform size and shape except the largest tread run within any flight of stairs shall not exceed the smallest by more than 3 8 inch.
Use different floor finishes to lead to the staircase.
The greatest riser height within any flight of stairs shall not exceed the smallest by more than 3 8 inch.
Private stairways serving an occupant load of less than 10 and stairways to unoccupied roofs may be constructed with an 8 inch maximum rise and a 9 inch minimum run.
Maximum 12 3 vertical height rise for a flight of stairs.
Handrail graspability to be either type i or ii with a minimum 1 1 2 inch clearance from a wall.
Lay out the stairs.
That said open risers within a dwelling even if approved with a less than 4 opening for the risers may still become useless or illegal if the stairs are egress stairs and are required to have their underside protected with drywall to provide a quick evacuation in even of a fire.