You can't take a tax deduction for the use of property or for a donation of a partial interest. If you give them the property and they take title that is certainly a deductible donation. But if you allow a charity to use property for free, there can't be deducted. Deductions reduce your income and since you never recieved income, you have nothing to deduct.
Or to put it another way, if you normally charge $100 per day for the facility, you can deduct a $100 donation if also report $100 of income (so it's a wash).
However, if you pay expenses out of pocket, that may be deductible. For example, if you normally pay a custodian $20 to clean the facility after each use, and normally take that from the rent money, and now pay it out of pocket, you can deduct that $20 if you pay to have the facility cleaned after the church uses it. Theoretically you can deduct any out of pocket costs that are attributable to the charity's use of the property, like utilities and cleaning. The problem will be proving the amount of the expenses that are directly attributable to the charitable use and that you would not have incurred these expenses but for the donated use.
