(b) A garden-type maisonette dwelling project is a series of attached, detached or semi-detached dwelling units which are provided as a group collectively with all essential services such as, but not limited to, water supply and house sewers, and which units are located on a site or plot not less than twenty thousand square feet in area under common ownership and erected under plans filed with the department on or after April eighteenth, nineteen hundred fifty-four, and which units together and in their aggregate are arranged or designed to provide three or more apartments.
9. A class B multiple dwelling is a multiple dwelling which is occupied, as a rule, transiently, as the more or less temporary abode of individuals or families who are lodged with or without meals. This class includes hotels, lodging houses, rooming houses, boarding houses, boarding schools, furnished room houses, lodgings, club houses, and college and school dormitories.
10. A converted dwelling is a dwelling (i) erected before April eighteenth, nineteen hundred twenty-nine, to be occupied by one or two families living independently of each other and subsequently occupied as a multiple dwelling or (ii) a dwelling three stories or less in height erected after April eighteenth, nineteen hundred twenty-nine, to be occupied by one or two families living independently of each other and subsequently occupied by not more than three families in all, with a maximum occupancy of two families on each floor in a two story building and one family on each floor in a three story building. A converted dwelling occupied as a class A multiple dwelling is a class A converted dwelling; every other converted dwelling is a class B converted dwelling.