S-CORP and OWNER SHAREHOLDER EMPLOYEE OF COMMERCIAL BULDING

should have a Schedule E

If he owns the building, he's not paying rent. How can the S Corp reimburse him for rent?

"Can he use accountable plan for reimbursement of rent"

Accountable plan means that a person paid, personally, for a business expense owed by their employer, and owed to the party which is owed the amount typically for goods and services, and that is a reasonable and customary expense for that business, and can be proven (shown to be accurate and incurred).

You seem to want the shareholder-employee to pay themselves (as landlord) a rent, then turn in the receipt to themselves (as employer) to be repaid?

What typically is done, is the S Corp has a lease agreement with the LLC or individual who owns the building, and the S Corp pays rent to the landlord (as usual) and would issue a 1099-Misc for Rent expense. The landlord has Rental Income to report personally.

There is no need to bring a circular process into it, as Accountable Plan.

But self-rental rules come into play here. You can google:

self-rental S Corp