(a) Off-street parking spaces required.
(1) In all districts, for all uses, there shall be provided, at the time any building or structure is erected or enlarged or increased in capacity, or at any time any other use is established, off-street parking spaces for motor vehicles in accordance with the requirements specified in this section.
(2) The off-street parking or loading facilities required for the uses mentioned in these regulations shall be the same lot as the structures intended to be served, on a lot abutting the lot intended to be served, or on a lot separated from the lot intended to be served only by a street not classified as a collector or an arterial by the city's thoroughfare plan. Such parking spaces shall be in a district permitting the use which they serve; provided, however, that in R-3, LB, GB, O-2, O-C, FP and I zoning districts parking shall be allowed for any adjacent use.
(b) Parking for existing uses. (1) It is the intent of these regulations to preserve and retain existing off-street parking and loading spaces in at least the minimum amounts as would be required if the existing use of the structure had been established or erected in full compliance with these provisions.