All residential leases in California have an implied warranty of habitability. This means that the landlord must do necessary maintenance to the apartment throughout the period of the lease and ensure it is “tenantable.” Before 1974, tenants were viewed as acquiring a property interest in the apartment they rented. Therefore, they were responsible for maintaining their own apartments
In 1974, the California Supreme Court decided the case of Green v. Superior Court. In Green, the court decided that, instead of analyzing a lease as a property interest, the lease should be viewed as a contract between the landlord and tenant. That way, since a landlord has greater bargaining power than the tenant, the landlord has an obligation to provide an apartment free from significant defects. In exchange, the tenant has an obligation to pay rent for an apartment free from significant defects.
An apartment is considered “tenantable” if it contains the following: effective weather protection; plumbing and gas lines in good working order; water lines that produce hot and cold running water; effective heating system; electrical system maintained in good working order; clean and sanitary premises; adequate number of trash receptacles; floor, stairways and railings maintained in good repair; proper security devices, and carbon monoxide detectors. Any apartment that does not have these items is considered substandard.