Q. What are the NEC lighting and switching requirements for stairways?
A. In dwelling units, not less than one wall switch-controlled lighting outlet must be installed [210.70(A)(2)(a)]. Where the stairway between floor levels has six risers or more, a wall switch must be located at each floor level and at each landing level that includes an entryway to control the illumination for the stairway [210.70(A)(2)(c)].
There are no NEC requirements for lighting or switching in other than dwelling units, because this is a design issue.