Staircase code states that stairs must be 3 feet wide or wider.
Building basement stairs code.
Irc stair railing code.
Maximum 12 3 vertical height rise for a flight of stairs.
Building codes often require insulation and moisture barriers.
These are two model codes and are offered as suggested guidelines for local code authorities to follow at their discretion.
The international residential code for one and two family dwellings irc and the international building code ibc address staircase railings.
At the same time staircase code measurements do allow for some flexibility since most measurements are accompanied by minimums or maximums.
There may be local or state building codes for how many inches off center you can space studs such as 16 or 24 inches apart and how much clearance you need for ceilings landings for the bottom of stairs and the height and depth of the steps.
The nosing on treads believe it or not has a code minimum and maximum of how far the nosing projects over the next stair.
This stair would have 16 treads 9 deep for a total run of 11 3.
To a maximum of 1 in.
Minimum 6 8 headroom height clearance for stairway.
A prime example is the standard stair width.
As long as the 3 foot width standard is met you can expand the stairs width as far as you wish.
From the top flight of stairs to the bottom of the stairs each individual riser cannot exceed a difference of 3 8 of an inch.
This becomes an issue when stairs are installed in tight locations under codes that vary greatly from today s current international building code ibc variants.
Nosings are required to overhang a minimum of in.