Mobile homes shall be so located on each space that there will be at least a twenty (20) foot clearance between mobile homes; provided, however, with respect to mobile homes parked end to end, the end-to-end clearance may be less than twenty (20) feet but not less than fifteen (15) feet; mobile homes shall be set back a minimum of ten (10) feet from sidewalks, and set forward a minimum of five (5) feet from the rear line of the mobile home lot space. In determining the clearance requirements, an annex shall be considered an integral part of the mobile home; provided, however, where the annex is less than half of the length of the mobile home to which it is attached, the clearance may be less than twenty (20) feet, but not less than fifteen (15) feet. No mobile home shall be located closer than fifteen (15) feet from any building within the mobile home park.