From: https://www.clergyfinancial.com/can-a-minister-deduct-home-office-expenses-and-receive-a-housing-all...

"The answer to this question is no.

A 1964 Tax Case (Deason v. Commissioner) stated that any deduction related to tax-exempt income cannot be claimed. Deducting income for clergy housing and then deducting again for a home office at that same location would amount to taking a double deduction, which is not allowed. In general, the Clergy Housing allowance is a far better deduction than the home office deduction, so if you have a choice between the two, you want to go with the Housing Allowance."