Converted on Multifamily Lot. One (1) or more ADUs within portions of existing multifamily dwelling structures that are not used as livable space, including but not limited to storage rooms, boiler rooms, passageways, attics, basements, or garages, if each converted ADU complies with State building standards for dwellings. Under this subsection (A)(3), at least one (1) converted ADU is allowed within an existing multifamily dwelling, up to a quantity equal to twenty-five (25) percent of the existing multifamily dwelling units.