he is an individual who is not a trustee, a trustee for beneficiaries who are all individuals or a personal representative,

the dwelling is a defective dwelling within the meaning of this Part by virtue of a designation under section 528 (designation by Secretary of State) or section 559 (designation under local scheme),

he holds a relevant interest in the dwelling, as defined in section 530, and

the conditions specified in section 531 (conditions of eligibility: disposal by public sector authority, &c.) are satisfied;