Unless otherwise permitted by this title or in subsections (b) or (c) of this section, parking spaces must be surfaced and maintained with a dustless all-weather material in accordance with the Baltimore City <cite data-path="|building-codes|II">Building Code</cite>. For single-family detached and semi-detached dwellings, a parking space may consist of 2 parallel paved parking strips, each of which is at least 18 inches wide and at least 18 feet long. For single-family detached, semi-detached, and rowhouse dwellings, driveways may be constructed of semi-pervious materials, such as grass-crete, pervious pavers, and gravel. Ord. 16-581 Ord. 18-171