24 CFR §982.604

1. (a)For a person residing in SRO housing, the payment standard is 75 percent of the zero-bedroom payment standard amount on the PHA payment standard schedule. For a person residing in SRO housing in an exception area, the payment standard is 75 percent of the HUD-approved zero-bedroom exception payment standard amount.
2. (b)The utility allowance for an assisted person residing in SRO housing is 75 percent of the zero bedroom utility allowance.