Representative architectural elevation drawings for all proposed structures shall be submitted and shall be subject to approval of the Planning Department and shall include height, building design, color, materials, signs and exterior mechanical equipment. All exterior walls shall be completed with finished building materials that shall provide for architecturally compatible building design. The design of all buildings within this district shall conform to a high-quality industrial/office building design and shall not feature retail design elements. A building permit shall not be issued until said plans are approved by the Planning Department.