24 CFR §1005.403

1. (a)Principal Residence. Means the dwelling where the Indian Family Borrower maintains as a permanent place of abode. An Indian Family Borrower may have only one Principal Residence at any one time.
2. (b)Occupancy requirement. An Indian Family Borrower must occupy the property as a Principal Residence. Borrowers who are a TDHE or a Tribe do not need to occupy the property as a Principal Residence and are not subject to the occupancy requirement.
3. (c)Non-occupant co-Borrower. A co-Borrower who does not occupy the property as a principal resident is permitted and is not subject to paragraphs (a) and (b) of this section. A non-occupant co-Borrower must be related by blood, or an unrelated individual who can document evidence of a family-type, longstanding, and substantial relationship not arising out of the loan transaction. A non-occupant co-Borrower must meet all other applicable requirements of this subpart and any requirements as may be established in Section 184 Program Guidance.