California Code, Health and Safety Code - HSC § 19872

(a) An enforcement agency may require as a condition of receiving a building permit, that a permittee participate in a preconstruction conference prior to completion of plan checking of the permittee's submitted plans and specifications for the purpose of reviewing the plans to ensure consistency of building code interpretations, and adequacy and sufficiency of plan details.

(b) If an enforcement agency requires a preconstruction conference, that enforcement agency shall request the participation of any other appropriate enforcement agencies of the local agency who may inspect a construction or renovation project.

(c) An enforcement agency may require the permittee to maintain at the site of the construction or renovation project, a set of plans and specifications that reflect any points of discussion, understandings, and agreements derived from the preconstruction conference.