Commercial buildings have tons of bathrooms on each floor, and they have janitorial closets that can be converted into shower stalls as they already have the drains installed for mop buckets and such.
Cal/OSHA’s requirements for toilet facilities are detailed at 8 CCR 3364. Separate toilet facilities for each sex must be provided as follows:
1 to 15 employees: 1 water closet
16 to 35 employees: 2 water closets
36 to 55 employees: 3 water closets
56 to 80 employees: 4 water closets
81 to 110 employees: 5 water closets
111 to 150 employees: 6 water closets
Over 150 employees: 1 additional water closet for each additional 40 employees or fraction thereof
I used to work for an employer that had one entire floor of a high rise—about one hundred and fifty cubicles with twenty or so offices in window locations.
There were two very large bathrooms.
Two.
There were zero showers.