In all zones, off street parking facilities for the storage or parking of motor vehicles for use of occupants, employees, and patrons of the building hereafter erected, altered, or extended, and all uses of the land after the effective date of this ordinance, shall be provided and maintained as herein prescribed. However, where a building permit has been issued prior to the date of adoption of this ordinance and provided that construction has been begun within ninety (90) consecutive calendar days of such effective date, off street parking facilities in the amounts required by this ordinance shall prevail.
   Computation of Parking Spaces  In determining the number of parking spaces required, if such spaces result in fractional parts thereof, the number of said spaces required shall be construed to be the next highest whole number.
   Additional Parking Spaces to be Provided  Whenever the intensity of use of any building, structure, or premises shall be increased through addition of dwelling units, gross floor area, seating capacity, change of use, or other units of measurement specified herein, additional parking spaces shall be provided in the amounts hereafter specified for that use, if the existing parking space is inadequate to serve such increase in intensity of use.