In the Residential Detached zones, the minimum lot width at the front building line and setback requirements for a principal building or an accessory building or structure may be reduced if:
A. the lot is located in an historic district designated on the Master Plan for Historic Preservation;
B. the Planning Board finds in a site plan under Section 7.3.4 that the reductions serve the purpose of maintaining the historic development and building patterns as evidenced throughout the surrounding designated historic district; and
C. the reduction is approved by the Historic Preservation Commission through the Historic Area Work Permit process Chapter 24 (24A-7).