California Code, Health and Safety Code - HSC § 17970.7

(1) Include criteria that inspectors or code enforcement officers shall use to determine if the substandard condition could reasonably affect other units, taking into account factors, including, but not limited to, the building type, age, size, type of construction, cause of the substandard condition, and history of violations.

(2) Require inspectors or code enforcement officers to reasonably attempt to inspect additional units at the property, including at least units adjacent to, above, and below the unit in which the defect or violation was found, consistent with existing law and inspection practices.

(3) Allow for the inspection of all of the units on the premises if severe, buildingwide defects or violations are found.

(c)(1) Upon determining that a substandard condition in a unit could reasonably affect other units, the local enforcement agency shall provide the property owner with a notice or order to repair or abate within a reasonable time after the inspection is completed.

(2) The local enforcement agency shall advise the owner or operator of each known violation and of each action required to remedy the violation and schedule a reinspection to verify correction of the violations.