This chapter shall apply as follows:
(1) For all buildings and structures erected and all uses of land established after June 19, 1986, accessory parking and loading facilities shall be provided as required by the regulations of the district in which such buildings or uses are located. However, where a building permit has been issued prior to that date, and provided that construction is begun within six (6) months of such date and diligently prosecuted to completion, parking and loading facilities as required hereinafter need not be provided;
(2) When the intensity of use of any building, structure or premises is increased through addition of dwelling units, gross floor area, seating capacity, or other units of measurement specified herein for required parking or loading facilities, parking and loading facilities shall be provided for such increase in intensity of use;
(3) Whenever the existing use of a building, structure or premises is hereafter changed to a new use, parking or loading facilities shall be provided as required for such new use. However, if this building or structure was erected or use established prior to June 19, 1986, additional parking or loading facilities are mandatory only in the amount by which the requirements for the new use would exceed those for the existing use if the latter were subject to the parking and loading provisions of this title;
(4) Whenever a parking lot is voluntarily upgraded without a change in or intensification of use, the parking lot shall reflect an improvement towards meeting the design provision of this chapter. Irrigation systems shall be required for any new planting areas proposed;
(5) At the time of erection or enlargement of any building containing one (1) or more dwelling units, or the addition of one (1) or more dwelling units to or within an existing building, there shall be provided and maintained garage and parking spaces for each such new or added dwelling unit as required by this chapter. Each existing unit that does not comply with this chapter shall be provided with at least one (1) garage space. That portion of existing parking that exceeds the requirements of this chapter may be reassigned to the added units.