See https://www.irs.gov/publications/p526#en_US_2022_publink1000229721
Partial Interest in Property
Generally, you can't deduct a charitable contribution of less than your entire interest in property.
Right to use property.
A contribution of the right to use property is a contribution of less than your entire interest in that property and isn't deductible.
Example 1.
You own a 10-story office building and donate rent-free use of the top floor to a qualified organization. Because you still own the building, you have contributed a partial interest in the property and can't take a deduction for the contribution.
