California CodesBusiness and Professions Code - BPCDivision 3 — Professions and Vocations GenerallyChapter 9 — ContractorsArticle 7 — Disciplinary ProceedingsSection 7109

(a) A willful departure in any material respect from accepted trade standards for good and workmanlike construction constitutes a cause for disciplinary action, unless the departure was in accordance with plans and specifications prepared by or under the direct supervision of an architect.

(b) A willful departure from or disregard of plans or specifications in any material respect, which is prejudicial to another, without the consent of the owner or his or her duly authorized representative and without the consent of the person entitled to have the particular construction project or operation completed in accordance with such plans or specifications, constitutes a cause for disciplinary action.