It's exciting you're all looking to build credit! Right now, we don't have a solution where roommates can build credit using one rent check. We're looking into building that feature very soon.
Right now, the only possible workaround is to have each person setup an account and split the rent payment.
You'll have to pay the technology fee on each check that you're sending, but we think it's incredibly reasonable for the credit & convenience benefit you're getting.