GOV § 66331

In enforcing building standards pursuant to Article 1 (commencing with Section 17960) of Chapter 5 of Part 1.5 of Division 13 of the Health and Safety Code for an accessory dwelling unit described in subdivision (a) or (b), a local agency, upon request of an owner of an accessory dwelling unit for a delay in enforcement, shall delay enforcement of a building standard, subject to compliance with Section 17980.12 of the Health and Safety Code:

(a) The accessory dwelling unit was built before January 1, 2020.

(b) The accessory dwelling unit was built on or after January 1, 2020, in a local jurisdiction that, at the time the accessory dwelling unit was built, had a noncompliant accessory dwelling unit ordinance, but the ordinance is compliant at the time the request is made.