Health & Saf. Code, § 16020

Periodically, as the work of construction or alteration progresses and whenever the enforcement agency requires, except as exempt under Section 16010, the architect, civil engineer, or structural engineer in general responsible charge of the work of construction, and the registered engineer shall make a report, duly verified by him or her through periodic review of construction, showing that the work during the period covered by the report has been performed and that the materials used and installed are in accordance with the approved drawings and specifications, setting forth any detailed statements of fact required by the enforcement agency.

“Periodic review of construction,” as used in this section and as applied to the architect, civil engineer, or structural engineer and the registered engineer, means the knowledge which is obtained from periodic visits to the project site of reasonable frequency for the purpose of general observation of the work, and also which is obtained from the reporting of others as to the progress of the work, testing of materials, inspection and superintendence of the work that is performed between those periodic visits of the architect, civil engineer, or structural engineer, or the registered engineer. The exercise of reasonable diligence to obtain the facts is required. The term “periodic review of construction” does not include responsibility for superintendence of construction processes, site conditions, operations, equipment, personnel, or the maintenance of a safe place to work or any safety in, on, or about the site of work.