Residential dwelling means:
(1) A single-family dwelling, including attached structures such as porches and stoops; or
(2) A single-family dwelling unit in a structure that contains more than one separate residential dwelling unit, and in which each such unit is used or occupied, or intended to be used or occupied, in whole or in part, as the residence of one or more persons.
40 CFR § 745.103
The following definitions apply to this subpart.