Cal. Civ. Code § 1942.4

(a) A landlord of a dwelling may not demand rent, collect rent, issue a notice of a rent increase, or issue a three-day notice to pay rent or quit pursuant to subdivision (2) of Section 1161 of the Code of Civil Procedure, if all of the following conditions exist prior to the landlord’s demand or notice:
(1) The dwelling substantially lacks any of the affirmative standard characteristics listed in Section 1941.1 or violates Section 17920.10 of the Health and Safety Code,
or is deemed and declared substandard as set forth in Section 17920.3 of the Health and Safety Code because conditions listed in that section exist to an extent that endangers the life, limb, health, property, safety, or welfare of the public or the occupants of the dwelling.
(2) A public officer or employee who is responsible for the enforcement of any housing law, after inspecting the premises, has notified the landlord or the landlord’s agent in writing of his or her obligations to abate the nuisance or repair the substandard conditions.
(3) The conditions have existed and have not been abated 35 days beyond the date of service of the notice specified in paragraph (2) and the delay is without good cause. For purposes of this subdivision, service shall be complete at the time of deposit in the United States mail.
(4) The conditions were not caused by an act or omission of the tenant or lessee in violation of Section 1929 or 1941.2.
(b) (1) A landlord who violates this section is liable to the tenant or lessee for the actual damages sustained by the tenant or lessee and special damages of not less than one hundred dollars ($100) and not more than five thousand dollars ($5,000).
(2) The prevailing party shall be entitled to recovery of reasonable attorney’s fees and costs of the suit in an amount fixed by the court.
(c) Any court that awards damages under this section may also order the landlord to abate any nuisance at the rental dwelling and to repair any substandard conditions of the rental dwelling, as defined in Section 1941.1, which significantly or materially affect the health or safety of the occupants of
the rental dwelling and are uncorrected. If the court orders repairs or corrections, or both, the court’s jurisdiction continues over the matter for the purpose of ensuring compliance.
(d) The tenant or lessee shall be under no obligation to undertake any other remedy prior to exercising his or her rights under this section.
(e) Any action under this section may be maintained in small claims court if the claim does not exceed the jurisdictional limit of that court.
(f) The remedy provided by this section may be utilized in addition to any other remedy provided by this chapter, the rental agreement, lease, or other applicable statutory or common law. Nothing in this section shall require any landlord to comply with this section if he or she pursues his or her rights pursuant to Chapter 12.75 (commencing with Section
7060) of Division 7 of Title 1 of the Government Code.