Off-street parking facilities shall be provided at a ratio of two parking spaces for each dwelling unit. If garages are included as part of this requirement, the first garage space shall count as 1/2 parking space and the second garage space shall count as a full space. Where garages are provided, the remaining required parking spaces may be provided in off-street lots, in the driveway area between a garage and sidewalk or curb if no sidewalk is to be constructed, or as parallel on-street parking. Wherever any of the parking requirement is provided as on-street parking, each such space shall be counted as only 1/4 space in determining the compliance with this standard, and the layout and width of proposed streets shall reflect the intention of utilizing on-street parking. In any event, no parking space shall be more than 150 feet from the unit it is intended to serve. This distance shall be measured from the front door of the unit along the route reasonably expected to be used by the occupant of the unit.