Whenever it shall appear to the commissioner that there has been a violation of any code, rule or regulation of the department promulgated pursuant to this article, the commissioner shall cause to have issued and served upon the alleged violator a written notice, which shall specify the provision of the code, rule or regulation of which such person is said to be in violation, a statement of the manner in, and of the extent to which, such person is said to violate it, and the order which the commissioner proposes to issue, and shall require such person to answer the charges of such complaint at a public hearing before the commissioner at a time not less than fifteen days after the date of notice. The commissioner may modify the proposed order following the hearing or upon the consent of the alleged violator. The alleged violator may, at any time, waive such right to a public hearing.