Holders of any site plan, conditional use permit, administrative use permit approval, interim use permit or variance may propose amendments to the permit at any time, following the procedures for a new permit as set forth in this Chapter. Administrative approval may be granted, for administrative use permits as set forth in City Code Section 11-2-7. No significant changes in the circumstances or scope of the use shall be undertaken without review by the Planning Commission and approval by the City Council. The Community Development Director shall determine what constitutes a significant change and may administratively approve insignificant changes. Significant changes include, but are not limited to, hours of operation, number of employees, expansion of structures and/or premises, different and/or additional signage, and operational modifications resulting in increased external activities and traffic, and the like. The Planning Commission may recommend, and the City Council may approve significant changes and modifications to a site plan, conditional use permit, interim use permit or variance, including additional or revised conditions.