24 CFR § 982.617 - Shared housing: Rent and voucher housing assistance payment.
(a) Meaning of pro-rata portion. For shared housing, the term “pro-rata portion” means the ratio derived by dividing the number of bedrooms in the private space available for occupancy by a family by the total number of bedrooms in the unit. For example, for a family entitled to occupy three bedrooms in a five bedroom unit, the ratio would be 3/5.
(b) Rent to owner: Reasonable rent.
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