Landlords are required to maintain their rental unit in a condition fit for the “occupation of human beings.” In addition, the rental unit must “substantially comply” with building and housing code standards that materially affect tenants’ health and safety.

A rental unit may be considered uninhabitable (unlivable) if it contains a lead hazard that endangers the occupants or the public, or is a substandard building because, for example, a structural hazard, inadequate sanitation, or a nuisance endangers the health, life, safety, property, or welfare of the occupants or the public.

Rentals may be considered uninhabitable (unlivable) if it substantially lacks any of the following:

• Effective waterproofing and weather protection of roof and exterior walls, including unbroken windows and doors.
• Plumbing facilities in good working order, including hot and cold running water, connected to a sewage disposal system.
• Gas facilities in good working order.
• Heating facilities in good working order.
• An electric system, including lighting, wiring, and equipment, in good working order.
• Clean and sanitary buildings, grounds, and appurtenances (for example, a garden or a detached garage), free from debris, filth, rubbish, garbage, rodents, and vermin.
• Adequate trash receptacles in good repair.
• Floors, stairways, and railings in good repair.

In addition to these requirements, each rental unit must have all of the following:

• A working toilet, wash basin, and bathtub or shower. The toilet and bathtub or shower must be in a ventilated room that allows privacy.
• A kitchen with a sink that cannot be made of an absorbent material such as wood.
• Natural lighting in every room through windows or skylights. Windows in each room must be able to open at least halfway for ventilation, unless a fan provides mechanical ventilation.
• Safe fire or emergency exits leading to a street or hallway. Stairs, hallways, and exits must be kept litter-free. Storage areas, garages, and basements must be kept free of combustible materials.
• Operable dead bolt locks on the main entry doors of rental units, and operable locking or security devices on windows.
• Working smoke detectors in all units of multi-unit buildings, such as duplexes and apartment complexes. Apartment complexes also must have smoke detectors in common stairwells.
• A locking mailbox for each unit. The mailboxes must be consistent with the United States Postal Service standards for apartment housing mailboxes.
• Ground fault circuit interrupters for swimming pools and anti-suction protections for wading pools in apartment complexes and other residential settings (but not single-family residences).

Source: California Tenants—A Guide to Residential Tenants’ and Landlords’ Rights and Responsibilities written by the California Department of Consumer Affairs’ Legal Affairs Division.