Cal. Civ. Code § 55.1-1220

A. The landlord shall:
1. Comply with the requirements of applicable building and housing codes materially affecting health and safety;
2. Make all repairs and do whatever is necessary to put and keep the premises in a fit and habitable condition;
3. Keep all common areas shared by two or more dwelling units of a multifamily premises in a clean and structurally safe condition;
4. Maintain in good and safe working order and condition all electrical, plumbing, sanitary, heating, ventilating, air-conditioning, and other facilities and appliances, including elevators, supplied or required to be supplied by him;
5. Maintain the premises in such a condition as to prevent the accumulation of moisture and the growth of mold and promptly respond to any notices from a tenant as provided in subdivision A 10 of § 55.1-1227 . Where there is visible evidence of mold, the landlord shall promptly remediate the mold conditions in accordance with the requirements of subsection E of § 8.01-226.12 and reinspect the dwelling unit to confirm that there is no longer visible evidence of mold in the dwelling unit. The landlord shall provide a tenant with a copy of a summary of information related to mold remediation occurring during that tenancy and, upon request of the tenant, make available the full package of such information and reports not protected by attorney-client privilege. Once the mold has been remediated in accordance with professional standards, the landlord shall not be required to make disclosures of a past incidence of mold to subsequent tenants;
6. Provide and maintain appropriate receptacles and conveniences for the collection, storage, and removal of ashes, garbage, rubbish, and other waste incidental to the occupancy of dwelling units and arrange for the removal of same;
7. Supply running water and reasonable amounts of hot water at all times and reasonable air conditioning if provided and heat in season except where the dwelling unit is so constructed that heat, air conditioning, or hot water is generated by an installation within the exclusive control of the tenant or supplied by a direct public utility connection; and
8. Provide a certificate to the tenant stating that all smoke alarms are present, have been inspected, and are in good working order no more than once every 12 months. The landlord, his employee, or an independent contractor may perform the inspection to determine that the smoke alarm is in good working order.
B. The landlord shall perform the duties imposed by subsection A in accordance with law; however, the landlord shall only be liable for the tenant's actual damages proximately caused by the landlord's failure to exercise ordinary care.
C. If the duty imposed by subdivision A 1 is greater than any duty imposed by any other subdivision of that subsection, the landlord's duty shall be determined by reference to subdivision A 1.
D. The landlord and tenant may agree in writing that the tenant perform the landlord's duties specified in subdivisions A 3, 6, and 7 and also specified repairs, maintenance tasks, alterations, and remodeling, but only if the transaction is entered into in good faith and not for the purpose of evading the obligations of the landlord and if the agreement does not diminish or affect the obligation of the landlord to other tenants in the premises.