I don't see how that would be a problem. If 4 roommates are paying the same "balanced billing" amount, then all of them would have overpaid by the same amount. Each roommate would receive a refund for the amount they paid over the term of the lease less 1/4 of the year's utilities incurred.
I...
Below are portions of the lease in question:
"Rent per month: $xxx
Term (Months): 12
Commencement Date: August 1, 20xx
Termination Date: July 31, 20xx
SECURITY DEPOSIT (LAST FULL MONTH RENT): $xxx already on deposit with LANDLORD
PERMITTED USE: Private Residence"
"UTILITIES: Utilities...