Minimum Front Yard. Minimum front yard setback shall be 20 feet from the applicable lot line when considering the extension, expansion, or replacement of existing buildings and the construction of new buildings. However, upon a finding by the city building inspector that no impairment would occur to the public’s safety, or the ability of fire fighters or police to access the property in the event of an emergency, this setback may be administratively reduced by said official to 15 feet. Such a decision shall also be based upon the existing lot size and/or existing building placement.