Where alleys exist physically, new dwellings shall take access from the alley, with parking spaces at the rear of the property regardless of the prevailing pattern of access of homes on the block. Where an alley exists only as a right-of-way or is only partially constructed, the applicant shall complete the applicant's portion of the alley from side lot line to opposite side lot line, provided that, upon completion, such alley will provide vehicle access to the rear of the property. Where alleys do not exist either physically or as a right-of-way or a combination of both, or the completion of the applicant's portion of the alley will not result in vehicle access to the rear of the property, new dwelling units shall provide for vehicle access and parking consistent with the prevailing means of access and location of garages on the block. In new neighborhoods, the preference for vehicle access applies in the following order: a) rear-facing garages; b) side-facing garages; and c) front-facing garages.