Cal. Health & Safety Code § 118507

(a) Notwithstanding Chapter 4 (commencing with Section 401.0) of the California Plumbing Code (Part 5 of Title 24 of the California Code of Regulations), a city, county, or city and county may require new or renovated public toilet facilities within its jurisdiction to be designed, constructed, and identified for use by all genders instead of the design standards for separate facilities for men and women found in the applicable provisions in Chapter 4 of the California Plumbing Code.
If a city, county, or city and county exercises the authority provided in this subdivision, it shall do so by adopting an ordinance or resolution.
(b)
1. (1) Signs in compliance with Title 24 of the California Code of Regulations shall identify the restrooms for use by all genders.
2. (2) Single-user toilet facilities shall comply with the requirements of Part 5 of Title 24 of the California Code of Regulations.
3. (3) In multiuser toilet facilities, lavatories shall be located either in toilet rooms or grouped in an immediately adjacent common use area accessible to all users.
(c) This section shall become inoperative on the date that standards that address all-gender, multiuser facilities take effect in the California Building Standards Code (Title 24 of the California Code of Regulations) and as of that date this section is repealed.