Front yard. No front yard should be required when all frontage between two (2) intersecting streets lies within this district. However, when lots within this district are adjacent to and adjoining lots in an "R" District, all of which front upon the same street between two (2) intersecting streets, there should be established the same front yard setback for all the frontage as has been established in the abutting "R" District.
Exception: When existing buildings located in this district have already established a building line at the street line at a depth less than is required above, then all new buildings shall conform to the same building line, except for the first fifty (50) feet of the "B-1" District frontage adjacent to the "R" District, whereupon there shall be provided a front setback of not less than ten (10) feet.