24 CFR § 574.320 - Additional standards for rental assistance.
(a) If grant funds are used to provide rental assistance, the following additional standards apply:
(1) Maximum subsidy. The amount of grant funds used to pay monthly assistance for an eligible person may not exceed the difference between:
(i) The lower of the rent standard or reasonable rent for the unit; and
(ii) The resident's rent payment calculated under § 574.310(d).
(2) Rent standard. The rent standard shall be established by the grantee and shall be no more than the published section 8 fair market rent (FMR) or the HUD-approved community-wide exception rent for the unit size. However, on a unit by unit basis, the grantee may increase that amount by up to 10 percent for up to 20 percent of the units assisted.
(3) Rent reasonableness. The rent charged for a unit must be reasonable in relation to rents currently being charged for comparable units in the private unassisted market and must not be in excess of rents currently being charged by the owner for comparable unassisted units.
(b) With respect to shared housing arrangements, the rent charged for an assisted family or individual shall be in relation to the size of the private space for that assisted family or individual in comparison to other private space in the shared unit, excluding common space. An assisted family or individual may be assigned a pro rata portion based on the ratio derived by dividing the number of bedrooms in their private space by the number of bedrooms in the unit. Participation in shared housing arrangements shall be voluntary.