(a) After the designation by ordinance of a historic property or of a historic district, no material change in the appearance of the historic property or of a structure, site, or work of art within the historic district shall be made or be permitted to be made by the owner or occupant thereof unless and until application for a certificate of appropriateness has been submitted to and approved by the commission. Such application shall be accompanied by such drawings, photographs, or plans as may be required by the commission.

(b) The Department of Transportation and any contractors, including cities and counties, performing work funded by the Department of Transportation are exempt from this article. Local governments are exempt from the requirement of obtaining certificates of appropriateness; provided, however, that local governments shall notify the commission 45 days prior to beginning an undertaking that would otherwise require a certificate of appropriateness and allow the commission an opportunity to comment.