The DHCR may authorize an amendment to a complaint or application at any time on good cause shown, except that an applicant or complainant shall have the right to amend the application or complaint in writing prior to the time within which an answer may be filed.

Any amendment to an application or complaint shall be served upon all affected parties in the same manner as the original application or complaint.

When an application or complaint is amended after an answer has been filed, all affected parties may file an amended answer or reply within the time provided for the answer or reply.